A toaster plugged into my house is on a circuit in the main box with a 15 amp breaker. The main box is bonded. Your diagram of the main box seemed to imply the box isn’t bonded. As far as I know home main boxes are always bonded with a ground rod right there. I know I have an 8’ ground rod right below the main box.
it is one of those it depends things , portables don't need them while fixt installations require them and any time you connect a generator to a house you get one weather you want it or not.
For anyone watching this video, be assured that everything he explained in it is 100% correct for connecting to a residence. I can tell that he has been listening to Mike Holt, same as myself. Well explained and visualized! Thank you for this fantastic video! Very respectfully, Kevin
This has to be the clearest explanation of all these scenarios that I have found on the internet. Thank you so much for taking the time to put together such a thorough video and website!
He has great communicative skills. There are so few TH-camrs who can get so much info across in such a short lemgth of time. This is exactly what I was searching for. Many thanks.
A real good video and 100% correct from what I know. I can say the vast majority of backup generators and transfer switches I saw and worked on for many years are not correct. Generators were always bonded neutral and grounded to the frames. The ATS’s did not switch the neutral connection. I worked for a generator service company for 30 years. We tied in temporary backup power many many times when the fixed machine was broken or needed some kind of repairs. Our trailer mounted machines were also bonded, neutral and ground. Switched neutral transfer switches only started to become a regular thing in recent years. Just pointing out what I saw. Homeowner backup portables are rarely hooked up correctly. It’s a very complicated situation !
Finally, someone who describes bonding (or not) clearly !! Thank you for your time in setting this information up for us who don’t understand a whole lot about electricity and how it functions!
Excellent explanation for hooking up a generator to power a house in an emergency. Where I live in Ontario Canada the transfer switch must break L1, L2 and the neutral making the generator a separately derived power source with a bonded neutral and ground plate. This eliminates the possibility of a malfunction in the house of back feeding through the neutral and energizing the grid.
AMAZING video and associated article. You wouldn't believe how many hours I've wasted trying to figure out some key questions on this topic and only ended up more confused. Your video and article are so clear and lay everything out so cleanly. Fantastic work - thank you for taking the time to produce these incredibly helpful resources for anyone who's interested in connecting a generator for backup power.
Thank you very very much for the effort to make this video. I am not sure I fully understand yet being a new generator user but I will view this a few times and consult my electrician. Thank you kindly.
With the switch neutral (13:51 time stamp) I have everything setup this way bonding at the generator which should clear the fault. I do not have the ground rod at the generator. I do notice in your diagram there is still a ground wire path to earth at the service. If the fault is cleared with the bonding at the generator and path to earth at the service why is a rod needed at the generator? Thank you. Great video by the way !
Thanks that made it clear. Switched neutral transfer switches changes the generator to a designated "separately derived voltage system." Than its on a nec regulations for a bonded and also ground rods requirements.
This a lot of info, however, the best way to know if a generator needs a ground is to look at the manual. If it shows a ground lug in the owners manual and shows you how to hook it up - then my guess is that it is needed.
Thank you for this. I have an electrician replacing my 20 slot panel with a 30 slot to accommodate a ckt for my portable generator and power for an electric vehicle. I have a Westinghouse WGen9500. They are installing 50 amp ckt outside of my house an a Generator Lockout at the panel. Do I need Ground Rod for the generator?
You should also do a video on RV’s and generators. They are not the same as a residence utility connected system. This might be the exception to bonding N-G at the generator and not installing a ground rod. Best wishes, Kevin
Peopel should check their manuals. I have a Ford 9500W continuous dual fuel generator I plug into a transfer switch on my breaker. The manual specificaly states connect to a grounding rod with 8 AWG wire. There's a ground wire connection on the frame and I use a ground fitting connected to our water pipe that runs under the house. Great video, thanks.
The scenario from 9:48 to 13:15. Assuming no active faults, What level of hazard would it be to remove the incoming service ground bond. So you’d be running on generator with a floating neutral with no ground bond anywhere in the system. Assuming no active faults and you were to touch the neutral, would you become the ground bond?
I watched several videos on bonding by several electricians and was left more confused. You're video really helped me to understand it better. I'll have to consult my professional after installing an off grid solar inverter setup. It comes factory bonded internally, but my main panel on the house is already bonded. My manual interlock only transfers hots so I'm thinking I need to unbond the inverters internally which is possible. Weird thing is my generator receptical on the house is also bonded where the cord plugs into the house. That was wired by the electrician. Seems like two bonds to me. still confused.
I learned what Electricians consider a bonded ground.... thanks .... My previous buba understanding of bonded meant it was soldered... I now know that is not what a Bonded Ground is...
Electricity DC/AC will always find the shortness route toward the ground earth and that will eliminate or reduce greatly any bad situation as long as that ground rod is deep enough and not connected to the ground rod of the electrical house panel. When electricity service is cut from various bad situations, the ground or neutral of the electric panel may have live current from these various bad situations ( car accident hitting a electrical pole, lighting strikes, winds blow off power line or electrical poles,,, ) Thank you Cheers
I was hoping you would touch on breaker interlock systems for generators. Which kind of transfer switch would that be considered ? I am assuming since a main breaker doesn’t disconnect the neutral, it would be considered a ‘normal’ transfer switch and not a switched neutral therefore no grounding rod for generator and remove the generator bonding jumper ? Do I have that right ?
hi all, my portable inverter generator (which is not to be connected to house as we're offgrid) has a port for grounding cable. Is this to be used only if hooking up to a house mains panel/socket? if I use as stand alone, to power tools and drive a sub pump, do I need to attach a grounding wire/rod to my genny? thanks
This may seem like a silly question with an obvious answer, but would it be correct to say that a "ground-neutral plug" is simply a way to turn your generator into a "bonded" generator? Essentially accomplishing what your jumper does? Or is it something different and/or does something more? (Bonus question: And why would you NOT want to have a bonded generator?)
Just came across your video today you seem to have a grasp like no other on the issues of grounding and bonding. GREAT JOB!! Can you please help me with this scenario as to if, I’m on the right track or not. I’ve already asked 3 local electricians and they all gave me conflicting information. I have a 50-amp interlock breaker on my panel and a generator socket outside of my house for bad weather outages. I just purchased TWO (Harbor Freight), Predator 5000 W inverter generators @120v. I naïvely thought that adding them together with a parallel kit, sold by the same company would boost me up to 240 V and 10,000 W. I know now that’s not reality because, there are only 2 wire connections on that generator and the 240 V generator has 3. So I was thinking to build a combiner circuit so then each leg would be 5000 watts at 240 V. Here’s what I was planning, take a 30 amp, 120v plug out of each generator and connect them in a box with a 50-amp socket, tie together the neutrals and place them in their terminal position, combine the grounds place them in their terminal position, and lines 1 and 2 would go each in their opposite terminal locations. Will this work it seemed straightforward to me until I thought, would the 2 phases from 2 different generators clashing with each other? I thought of this because I saw a video about power plants needing to precisely spin up their generators to work with each other’s sine wave. Is this not an issue with inverter generators or in my scenario? Kind regards,
Thanks Robert. I think I get most of this, but I still have a question that I don't believe you covered. Does your " Do I need to Ground My Generator" slide apply when feeding an old 3 wire service house with a modern 4 wire generator?
Extremely thorough but Please maybe I missed it and I’m getting conflicting info from different sources including n manufacturers. My generator is neutrally grounded but is going to be hooked up w a 50 amp inlet plug on my home to the 50 amp breaker in my main with an interlock device. So in this direct connection I Do need a ground rod attached to generator ? And if so do I disconnect the neutral bond wire on the alternator? Thanks in advance. Just trying to get some clarification
If I want to back feed my shop that is fed via a 125A panel from a 3ph service without a master disconnect, can I interlock the feed breaker at the shop panel to a generator inlet breaker? Subpanel G and N are not bonded, so would generator need to remain bonded or does N at subpanel need to be transferred as well?
Great video. What if I'm backfeeding my house panel and I don't have a ground in my cord? Just 3 wires, 2 hots and a neutral. Is it OK to have the generator bonded?
If you're using your generator to charge/run your holiday trailer I would think you would want your generator neutral to be bonded as the neutrals and grounds would be separated in your main panel of your trailer. I would also think that if your trailer is connected to shore power the main power coming in would have the first point of disconnect so the grounds and neutrals are bonded together. Are my assumptions correct? Also when using the generator to charge the trailer and run extion cords ahould I install a ground rod for that application?
I have a question. So if you dont have utility power grid connected to a farm house and in your example replace the utility with an inverter. So with two power sources (generator and solar inverter system with a battery backup). My question with refference to a transferswitch that also switches neutral wire- here in your example you basically have two power sources's neutral wires connected with each other through a ground wire... does this not have potential bad effect? So the neutral wires of two power sources touch each other and both sources are generating potential but only one feeds a load - does this not pose any danger to the equipment?
If my gen was close enough and it is bonded when i break the neutral at transfer i have to have a ground rod could i use the one that the house is on since its broken att the transfer to keep me from putting another rod in the ground
SOMEONE PLEASE HELP! I have a bonded generator that I will be connecting to a mobile home. The first disconnect is outside by the meter. I'll be connecting to the subpanel inside, using an interlock. Will the main panel outside provide the bonded neutral, or should the generator be bonded? And with that setup, do I need a grounding rod? Thanks
Based on this information...I do not have a "switched neutral"...but I want to be sure. My electrician installed a twist-lock 30 amp box on the house next to my outside panel, ran 8-3 with ground to my outside panel....connected the two hot leads from the box to a 40 amp breaker inside the panel..and ran the neutral wire to the neutral bus bar and the ground to the ground bus bar. I can see that inside the panel the two bus bars are bonded, and I have a mechanical interlock preventing the main breaker from being on when the new 40 amp breaker is on. So I assume that I do NOT have a switched neutral set-up...(and that when power is out and main is switched off and locked) that I should run a "floating neutral generator" when plugged into that box, and that I don't need a ground rod. Am I correct in this? Thank you for a reply.
First of all, the 40 amp breaker is a code violation. The over current protection rating cannot exceed the rating of a single receptacle even though your 8-3 wire is oversized. You do not have any neutral switching since you have no transfer switch. Your ground and neutral bond at the generator needs to be separated and the neutral wire insulated. Install the ground rod and connect it to the frame of the generator or to the same terminal where you removed the neutral. Either way, use a proper set screw lug.
@@trustme7731 You are saying that the 40 amp breaker exceeds the rating of the 30 amp box and thus is a code violation...correct? I wondered about that.
@@spacecoastz4026 The breaker exceeds the rating of the 30 amp receptacle. That's not allowed for a single receptacle. In a perfect world the 30 amp generator breaker would protect it but who knows if it would fail or how this would be used by someone else.
great video ... how does the bonded and un bonded work when you have GFCI on generator ....or a motorhome with built in generator are they unbonded with GFCI plugs ?
What about a generator connected to a house via an inlet box directly to a breaker? That is to say no transfer switch. Does the generator need to be bonded and/or grounded? Thanks.
Hey thanks for the great video. Question: I have a 30amp single phase RV. I installed an automatic transfer switch so I can use an inverter, a generator, and shore power all separately and seamlessly. The transfer switch switches both the hot and the neutral leads… this way, I can use shore power when I’m home (that’s bonded at the panel) and a bonded generator, when I’m camping off-grid, and I can use my inverter when the generator isn’t running. My question is this- should I tie a ground wire from my inverter to the chassis of the Camper trailer? (The inverter has an external earth symbol with a screw for mounting a wire- but my sense is not to use this connection unless using the inverter in a house application). Also, interestingly, when I test the inverter with a meter, it only reads as a bonded ground when it’s turned on.. when it’s turned off, it reads as a floating neutral.
as I recall, in most RVs everything is floating till you plug into shore power, where the ground pin does the rest with the utility connection. Since it's a 120 volt system complete isolation can only take place if they disconnect the neutral. The answer for your inverter should be in the owner's manual, or available from the mfgr's tech support. They have the final word.
What about static electricity generated on the generator itself using the ubiquitous manual interlock with the neutral bonded to the ground at the panel. Still recommend no grounding rod at the generator? I think that static would be dissipated on the main panel grounding rod, correct? This is it awesome video. Thanks.
So, I'm using an interlock kit to connect my 12kw portable generator to my house. Am I correct to assume that, functionally speaking, this is electrically the same as your transfer switch with a fixed (non-switched) neutral? In which case, I should be unbondinding the neutral and ground at my generator, but NOT using a ground rod at the generator? Correct?
Old school wiring in the house. No three prong plug. Just neutral and hot. If a grounded generator is added when the local current is off, will it ground the house or go on as the same as it ever was? (No ground in the house.)
So quick question ... I have a circuit breaker box with 2 hots and 1 connection for either ground or Neutral there is a bar on both sides of the box that IS connected to each other SO my question is what do I do with the ground and neutral wires coming into the box with only one connection? do I twist the neutral and ground wires together and connect them to the LUG? The wires coming in are from a generator but there are 4 wires coming in and only three Lug screws in my box
This question can not be answered with information given. Not enough detail. Sounds like the panel is fed by a generator only, but nothing about how it is used and connected to what.
I just hooked my shop up to a transfer switch and when I connected my generator all of the GFCI breakers popped and cannot be reset. Is this because of a double bonding situation?
I have had a generator since 2003. I have never used it as a source for my high-efficiency gas furnace for fear that it would take out the $$$$$ control board. I was told that the generator puts out "dirty" voltage. More recently, I've read the problem is the ground and that the flame sensor will not see the spark ignite the flame and will shut down. How do I get a plane jane Generac generator to power my furnace. OBTW, there are videos out showing that expensive Honda generators, with floating ground, will not power up the furnace. My microwave will not run off of my generator either. I am using an extended version of the twist lock on the generator going to 4 each 120VAC outlets. Thanks.
Why do you show the neutral-ground bond at a service disconnect switch which is not part of the breaker panel? The vast majority of residential services have the neutral-ground bond in the breaker panel because the main breaker in the panel is the first point of disconnect. I'm sure such systems exist, but every residential panel I've worked on has the L1,L2,N service wires coming from the utility transformer to the meter (which is not a disconnect) and then to the main house panel, and the main breaker in that panel only disconnects L1 and L2. In this scenario it would not matter whether the transfer switch disconnects the neutral or not, you'd still need an unbonded generator.
Why do you need a ground rod at the generator though when you use a switched neutral transfer switch? the neutral is no longer shared, but the PE (ground wire) is still shared with the house, wouldn't it just use the grounding rod that the house uses by default?
It's not always possible without disassembling more than you want to. If you can do it, I suggest you add a warning label to the generator making it clear to never use it unless it's feeding a grounded building that already has the proper bond.
watched your video, I am setting up a bonded generator to a house with a interlock. someone told be to run a grounding wire from the generator to the same grounding rod used by the house, can you give me your opinion, i just want to be safe with generator and and not endanger any thing in the house, thanks
If you're using a 2 pole interlock kit (with unswitched neutral), you'll need to remove the bonding jumper in the generator and do not add a ground wire (or attach) to the ground rod .
Maybe I missed it but I have an Interlock Switch to change from utility service to my generator inside my breaker box. The 50 amp receptacle that the generator plugs into to provide power to the breaker box is grounded to the same ground rod as the breaker box and the meter coming from the street. So the breaker box is grounded whether power is coming from the street or from the generator. I’m confused now if I need to also add a grounding rod connected only to the generator.
Someone else asked the same question above, and spacecoastz gave the following excellent answer which I believe is correct: Here is an answer I found from Home Battery Bank in reference to an interlock system. I found it down below. "When properly installed, an interlock just makes it so that you can't have the mains power turned on while you're turning on the breaker that you're using to backfeed the house with your generator. The power line crews appreciate it! The neutral is left intact (and the house is already bonded) and the generator still shares it with the house. The generator should be floating neutral (unbonded) so that you don't have parallel paths for the return current (and any fault currents) back to the source (the generator). Of course, I recommend reaching out to your local certified electrician before you make any changes." You need to have a floating neutral generator and no additional ground rod
Thank you thank you thank you have internally grounded portable generator with a bonded neutral The guys that set up all of the cabling for a three-phase 120 208 system put in grounding rods in addition to bonding the three generators to themselves getting a reading from hot to ground of 120. Suspect that ground rods are not applicable or advised. Now I'll take this information and do more research but I think I've come to the conclusion that grounding rods should not be used on internally bonded isolated generators not attached to a house system. The only advantage is during a lightning strike from what I've learned from your video
So basically, if I'm using my generator to input to interlock into my electrical box, the generator should have a floating neutral since ground and neutral are already bonded inside my breaker box. If I'm using generator just with extension cords, then it should be bonded. correct?
Sounds dumb I know but....define "extension cord" in the context used here? ANY cord plugged into the generator or do you mean a suicide cord with male ends on both ends?
Very informative. I've watched this few times now and trying to relate it to my scenario to figure out how to wire things up safely. I have a generator that I will use to power my completely off pole shed. I'm planning to use 30 amp inlet wired into small sub-panel or main panel to power a few outlet (GFCI) and some lights. My question is where should I bond? Should I bond at generator or should I bond at panel (not connected to utility power)? Does it matter? I'm thinking I would want to bond at source, the generator, therefore keep grounds and neutrals separated at panel. But I'm not sure if that is right or not.. Still wrapping my head around it. Thanks.
I am trying to do this very same thing as you..did you find any answers for this? Lol..I’m thinking it NEEDS bonded at our panel bc that’s how it is in our homes and the transformers are ground neutral bonded and that would be like our generator(assuming the generator we have is bonded by manufacture
@@jeremysmothers5143 No. Unfortunately I have not been able to get straight answer to this question. I'm on several electrical forums and seems no one either knows or wants to tack this question. So I called a master electrician and he never called me back.
nice video, I have a question. I have a battery bank and I'm 90% off-grid I only use city power for powering up air-conditioners, the thing is my neutral (inverter) is bounded with the city power neutral which is bound at the main panel with their ground, should I isolate and install a ground rod and only switch to city neutral & ground when I'm using them? I don't live in the USA and the grounding practices here are less common. so this is not a question about regulations, but best practices.
Hi, thank you so much for the explanation. For a typical floating neutral generator and used with extension cords, will a grounding plug (making connection between neutral and ground), make it safer? What is your opinion on that? Thanks.
He already explained it at 10:00. Keep the generator floating neutral (don't bond neutral to ground at generator). Neutral is bonded to ground at the main panel.
@@urbanturbine thanks for the feedback. I was specifically asking for the case with extension cord. You are referring the case when the generator is hooked up to the house panel which makes sense to use the connection at the house and not have another neutral to ground bonding at the generator. I am wondering when an extension cord is used, whether a Ground to neutral plug should be used to at least get some protection from any hot to ground fault on any appliance with metal exterior.
@@bennettonline absolutely you can bond the generator with a grounding plug... just be sure to remove the grounding plug if you connect the generator to a typical transfer switch that does not switch the neutrals...
Hi could someone clarify for me when he says using an extension lead, would the toasters own lead with out an additional extension lead connected making it longer be safe connected directly to the generator? I'm assuming not, if it got a fault its the same right (toaster plugged directly into gen or with additional extension lead) I guess he says extension lead referring to when it's not hooked up to the house via switches. This really has me confused can someone help me understand. Thanks
Yep. When he's speaking of extension cords that is when you're just running cords from the generator's onboard plugs to certain things in the house but not connecting it to the home's wired electric system.
Home Battery Bank, my generator is neutral bonded to frame. I’m using an interlock with 30 amp 240V(L14-30R). I will consult a local electrician but was looking for your thoughts as well. I can very easily convert to floating neutral if that makes the situation better. Thanks,
it all depends on what king of transfer switch you have... if you have a typical transfer switch that only switches the hots, then you do NOT want it bonded at the generator... if you have a transfer switch that switches both the hots and the neutrals at the main panel - then you want the generator bonded AND you want to connect the generator to a ground rod... that's why hot/neutral transfer switches are not typical...
Good explanation. How about the situation where you are feeding a transfer switch with the 240 outlet from the gen and using an extension cord from one of the 120v outlets to power another appliance that is not on the gen transfer switch? Is it ok to have the gen be a floating neutral even when using the extension cord?
I'm no expert, but I would say yes. it's ok, since the neutral and ground are connected to the main service thru the extension cord, thru the generator, and back to the house. This is assuming you have a "hots only" transfer switch.
@@aspensulphateYeah. Basically the neutral should only be attached to the ground once. If the transfer switch doesn't disconnect the neutrals when transferring the the generator is always connected to the neutral of the building and the neutral of the building is always connected to its ground rod/plate.
I’m hoping you can clear up some confusion I have regarding generator protection devices and bonding. Specifically, I view circuit breakers as over-current devices which trip when their rated current is exceeded. Then there are GFI devices which I like to think of as differential current devices in the sense that they trip when the outflowing current on the hot wire does not equal the return current on the neutral wire. Can you elaborate as to how bonding effects each (or both?) of these devices? - Thanks! - Jim
Your understanding of both is correct. GFI requires No equipment ground to operate. Circuit breakers or fuses (overcurrent protective devices) have two functions. First, overcurrent (as you stated). Second, short circuit. The part that may be missing is the current path from a ground fault. Let’s say your hot in your electric heater, touches the metal case. Let’s start just past the circuit breaker at the lug. The path of current is, hot conductor to case. Case to equipment ground. Equipment ground to panel bus bar where both connected. Neutral to utility transformer. Utility transformer to panel power bus bar. Bus bar to breaker. Thousands of amps, magnetically trips the breaker. Hope this helps. Respectfully, Kevin
Is grounding to a copper water supply line (coming out of house for sprinkler system) an acceptable alternative to a grounding rod for my generator? It’s the same piping that my breaker panel is grounded to about 20’ ft upstream from this point.
a copper water pipe generally sufficed for a grounding rod years ago - but code now generally states that if you use a copper pipe for a ground rod, you also need a regular ground-rod sunk in the ground at least 6 feet away from the copper pipe (the further away the better)... in fact most electricians will now routinely sink two ground-rods to ground a panel... since you're connecting your generator to a ground rod - I assume your generator is bonded and you are also connecting your generator to your house through a hot/neutral transfer switch (where the neutral is also switched, which is not a common type transfer switch)...
I have a Champion inverter generator (4500/3500) with a floating neutral. I will be using a Reliance "through the wall" receptacle that is NOT grounded - it just splits a 120V 30 amp plug into standard wall plugs (6) through the wall into the interior of the house. Extension cords would be plugged into appliances and a portable A/C. Do I need to GROUND the generator using a grounding rod?
1. How do you know its a floating neutral? Portable generators come bonded. Test for continuity at the generator between a receptacle ground terminal and its neutral terminal. 2. I have no idea what a "through the wall receptacle" is. 3. If you are using cords from the generator receptacles to each individual piece of equipment in the house, then the generator ground and neutral must be bonded and no ground rod needed.
In summary: - If the transfer switch *doesn't switch* the neutrals, you *must not* _(i.e._ are not allowed to) bond the generator neutral to the generator ground, and you *are not required* (but are permitted) to ground the generator. - If the transfer switch *does switch* the neutrals, you *must* _(i.e._ are required to) bond the generator neutral to the generator ground, and you *must* _(i.e._ are required to) to ground the generator. Right?
be aware that sometimes the NEC rules may not be applicable. To wit: The National Electrical Safety Code (NESC) is a set of safety standards that govern the installation, operation, and maintenance of electric supply, communication lines, and related equipment. Contact your local utility before attaching any alternate source of energy in lieu of a utility transformer to your structure, they usually respond free of charge.....
To avoid electrocution with a fault present, I would rather not complete a circuit with a floating neutral generator than rely on a CB to pop in time in a bonded neutral generator. If I want to know if a fault is present (hot metal skin), then I can use a NCVT tester. Most people who bond their neutral to ground in a floating neutral generator are RV owners using surge protectors. For them, more about getting their surge protectors to work than an electrocution issue.
I'm thinking that the setup where the generator hooks up to directly to the neutral in the service could be problematic since the very reason for the outage could be a fault in that very neutral/ground!
If you convert a portable generator to a floating neutral, should you not use the outlets on the generator at the same time the generator is energizing the house through the house electrical panel? I'm wondering, since a neighbor has expressed interest in running an extension cord to the generator.
I don't see why you couldn't use those outlets since the neutral is bonded at the house and essentially they are no different than an outlet in your house. If you're talking about that neighbor connecting into your generator, I'd be more concerned about them exceeding the output of your generator and tripping your generator breaker.
3:39 if the neutral is not grounded then neither wire has potential compared to the ground so you can get shocked only between the wires, not between any wire and the ground so the fault would no cause any risk.
Newbie here. I use nothing but electrical chords to run some key items (freezer, etc) during a power outage. Per this video, I should bond my neutral. I'm not using the L5-30r socket on my generator (120v only generator, no 240v). Can I purchase a L5-30p plug and do the bonding within the plug? I makes for simple conversation back and forth between floating and bonded.
Get a bonding plug they are inexpensive on Amazon. It will plug into a 120 receptacle on the generator and the entire generator will be bonded including the 30 amp receptacle
Check your generator to see if its already bonded. See if there is continuity between the neutral socket opening (the wide one) and the round ground opening socket, using a meter. I had to move my meter leads around some before I made a good connection and found that I have a bonded generator.
@@brandonmurphy4657 see the comment from bradsmith5131 a few comments down. I have the same question and it appears that the generator needs to be floating neutral and no ground rod in the case of the interlock from what I am seeing.....
When properly installed, an interlock just makes it so that you can't have the mains power turned on while you're turning on the breaker that you're using to backfeed the house with your generator. The power line crews appreciate it! The neutral is left intact (and the house is already bonded) and the generator still shares it with the house. The generator should be floating neutral (unbonded) so that you don't have parallel paths for the return current (and any fault currents) back to the source (the generator). Of course, I recommend reaching out to your local certified electrician before you make any changes.
I don't have my generator on a 'frame', I have it on a steel metal garden cart, because it's easier for me to move, it's very heavy. Since the cart has for rubber wheels, would it be advisable to put a grounding rod in to attach to the cart? I used this generator last year here in East Texas when they froze us out for 3 days, had no problems, but what you have said about the frame being the ground for the generator now has me a bit worried. Thank you.
@@rupe53 ; sorry for the tardy reply, pc issues...sigh. Thank you for your response, I appreciate it, we're supposed to get slammed tonight with thunderstorms.
So my solar generator is a floating neutral and my transfer switch is Generac HomeLink, which switches the neutral from the grid neutral. The only thing shared in the transfer switch is the ground bar which is connected for both power sources. I would assume that if I used a generator grounding plug that bonds the neutral and the ground together on my solar generator this would meet the requirement to bond my solar generator when powering part of my home and gives it access to the homes' existing grounding system, which includes the grounding rod, yes? Thank you for this great video!
I would say you can test this with a meter. Flip your transfer switch to the standby power mode and see if ground and neutral are still tied together, measured at the plug where you connect your generator.
I have three main panels (2ea-200 amp, 1ea-100 amp) with individual meters ( 3 separate electric bills) feeding house, shop and well pump . All power from the power company is fed from one 35KW transformer. I have a 15 KW PTO (tractor powered) backup generator. I have a 125-amp sub-panel located near the generator. The sub-panel has 4 ea 50-amp double pole breakers. One breaker will be the input from the generator to the sub-panel. The three remaining breakers in the sub-panel will each be connected via a 50 amp breaker feeding power to the main panels for the house, shop, and well pump. The main panels will each receive a new 50-amp breaker and an interlock switch. The sub-panel and three main panels are connected with four conductor, 4awg underground aluminum wire. Each of the three main panels has its own interlock switch with a 50-amp double pole breaker. When in backup power mode each main panel will be powered by the generator through the sub panel if the 50 amp breaker in the sub-panel is on for the targeted main and the targeted main panel is in backup power mode via the interlock. My questions: how do I connect the neutral and ground from the generator to the main panels? I assume the generator neutral should be floating. Do I even need the ground wire from the generator to the main panels? does the generator need its own ground rod? Thanks for the help. I have ask several electrical engineers and gotten different opinions.
If “All” your three main panels are correctly installed (with bonding from N-G at each system), then there is no disconnecting that neutral. Therefore, you do not want a N-G in your generator. Also, what you are calling your sub panel, is a generator distribution panel. It receives no voltage or current from the main panels. Just my opinion.
If the neutral is connected using the neutral from the power company and the generator, would that not backfeed the grid? Aren't you technically trying to return the electricity back to the power company?
No, not via the utility neutral. You can only backfeed by completing a circuit with the utility ... meaning between the two utility legs or between the utility neutral and one leg. The neutral alone has no ability to backfeed anything. It just equalizes the potential of the neutral conductor on the utility transformer. No current actually flows.
What about it? Is the neutral being switched? That's the question you need to answer, and you need to act accordingly per the information in the video.
Check the comment above from bradsmith5131 concerning this issue. The generator needs to be converted to floating neutral with no ground rod if you're just using the interlock in your main panel. Many people confuse the simple interlock system with the more complicated transfer switch and it wasn't directly addressed in this video.
I always leave my generator bonded, because I've seen firsthand what damage happens to appliances in a home, if the neutral connection is suddenly lost.
I just bought a 12,000 watt portable generator. In the instructions it said that you need to use a ground otherwise you may get electrocuted. Then I realize that they didn't include a ground with the new generator LOL. Seems like they should include something simple and cheap that can save your life, just a simple rod and wire.
Probably just trying to cover themselves. I have found many places do not have a good ground. Ground rods are not cheap. They are thick, and if memory serves me correctly, must go below the frost line and/or reach a certain moisture level in the soil. Good thing to look up before you install one.😁
Read carefully. The word ground can be misleading. Is it saying or showing equipment ground, or grounding electrode conductor? Two totally different things. Be careful!
An easy way to tell if the generator neutral is already bonded is to use a continuity tester and check between the neutral and ground on one of the generator receptacles. If you have continuity, then you don't need a ground rod for standalone use.
![When You DO and DO NOT Need to Ground Your Generator [Extension Cord Use & Backfeeding a Home]](/img/n.gif)
Disclaimer: Always consult your local licensed electrician before making any changes to your setup. This video is for entertainment purposes only.
yeah any lawyer will blow right thru that lame ass disclaimer....if you aint a licensed electrician, you shouldn't be giving advice.
Nice.
A toaster plugged into my house is on a circuit in the main box with a 15 amp breaker. The main box is bonded. Your diagram of the main box seemed to imply the box isn’t bonded. As far as I know home main boxes are always bonded with a ground rod right there. I know I have an 8’ ground rod right below the main box.
it is one of those it depends things , portables don't need them while fixt installations require them and any time you connect a generator to a house you get one weather you want it or not.
For anyone watching this video, be assured that everything he explained in it is 100% correct for connecting to a residence. I can tell that he has been listening to Mike Holt, same as myself. Well explained and visualized! Thank you for this fantastic video! Very respectfully, Kevin
This has to be the clearest explanation of all these scenarios that I have found on the internet. Thank you so much for taking the time to put together such a thorough video and website!
He has great communicative skills. There are so few TH-camrs who can get so much info across in such a short lemgth of time. This is exactly what I was searching for. Many thanks.
Great stuff 👍 good explanation so easy to understand. keep up d good work
What a great clear and concise explanation. So many have tried and so many have failed. You nailed it!
A real good video and 100% correct from what I know. I can say the vast majority of backup generators and transfer switches I saw and worked on for many years are not correct. Generators were always bonded neutral and grounded to the frames. The ATS’s did not switch the neutral connection. I worked for a generator service company for 30 years. We tied in temporary backup power many many times when the fixed machine was broken or needed some kind of repairs. Our trailer mounted machines were also bonded, neutral and ground. Switched neutral transfer switches only started to become a regular thing in recent years. Just pointing out what I saw. Homeowner backup portables are rarely hooked up correctly. It’s a very complicated situation !
Finally, someone who describes bonding (or not) clearly !! Thank you for your time in setting this information up for us who don’t understand a whole lot about electricity and how it functions!
Excellent explanation for hooking up a generator to power a house in an emergency. Where I live in Ontario Canada the transfer switch must break L1, L2 and the neutral making the generator a separately derived power source with a bonded neutral and ground plate. This eliminates the possibility of a malfunction in the house of back feeding through the neutral and energizing the grid.
AMAZING video and associated article. You wouldn't believe how many hours I've wasted trying to figure out some key questions on this topic and only ended up more confused. Your video and article are so clear and lay everything out so cleanly. Fantastic work - thank you for taking the time to produce these incredibly helpful resources for anyone who's interested in connecting a generator for backup power.
Thank you very very much for the effort to make this video. I am not sure I fully understand yet being a new generator user but I will view this a few times and consult my electrician. Thank you kindly.
With the switch neutral (13:51 time stamp) I have everything setup this way bonding at the generator which should clear the fault. I do not have the ground rod at the generator. I do notice in your diagram there is still a ground wire path to earth at the service. If the fault is cleared with the bonding at the generator and path to earth at the service why is a rod needed at the generator? Thank you. Great video by the way !
Thanks that made it clear. Switched neutral transfer switches changes the generator to a designated "separately derived voltage system." Than its on a nec regulations for a bonded and also ground rods requirements.
This a lot of info, however, the best way to know if a generator needs a ground is to look at the manual. If it shows a ground lug in the owners manual and shows you how to hook it up - then my guess is that it is needed.
Not necessarily. As he said, if the transfer switch also switches the neutral, only then would a ground rod and bond be required.
Thank you for this. I have an electrician replacing my 20 slot panel with a 30 slot to accommodate a ckt for my portable generator and power for an electric vehicle. I have a Westinghouse WGen9500. They are installing 50 amp ckt outside of my house an a Generator Lockout at the panel. Do I need Ground Rod for the generator?
So why does my small floating neutral generator have a ground terminal... Is that in case I wanted to use an extension cord?
You should also do a video on RV’s and generators. They are not the same as a residence utility connected system. This might be the exception to bonding N-G at the generator and not installing a ground rod. Best wishes, Kevin
Peopel should check their manuals. I have a Ford 9500W continuous dual fuel generator I plug into a transfer switch on my breaker. The manual specificaly states connect to a grounding rod with 8 AWG wire. There's a ground wire connection on the frame and I use a ground fitting connected to our water pipe that runs under the house. Great video, thanks.
The scenario from 9:48 to 13:15. Assuming no active faults, What level of hazard would it be to remove the incoming service ground bond. So you’d be running on generator with a floating neutral with no ground bond anywhere in the system. Assuming no active faults and you were to touch the neutral, would you become the ground bond?
I watched several videos on bonding by several electricians and was left more confused. You're video really helped me to understand it better. I'll have to consult my professional after installing an off grid solar inverter setup. It comes factory bonded internally, but my main panel on the house is already bonded. My manual interlock only transfers hots so I'm thinking I need to unbond the inverters internally which is possible. Weird thing is my generator receptical on the house is also bonded where the cord plugs into the house. That was wired by the electrician. Seems like two bonds to me. still confused.
so why do manufactures always print in the manual to inst a ground rod? I see this on gens that come with floating N and ones that are already bonded
I learned what Electricians consider a bonded ground.... thanks .... My previous buba understanding of bonded meant it was soldered... I now know that is not what a Bonded Ground is...
Electricity DC/AC will always find the shortness route toward the ground earth and that will eliminate or reduce greatly any bad situation as long as that ground rod is deep enough and not connected to the ground rod of the electrical house panel. When electricity service is cut from various bad situations, the ground or neutral of the electric panel may have live current from these various bad situations ( car accident hitting a electrical pole, lighting strikes, winds blow off power line or electrical poles,,, ) Thank you Cheers
this is why you ALWAYS isolate from utility when using an alternate power source.
Excellent video, very clear and answers all my questions.
I was hoping you would touch on breaker interlock systems for generators. Which kind of transfer switch would that be considered ?
I am assuming since a main breaker doesn’t disconnect the neutral, it would be considered a ‘normal’ transfer switch and not a switched neutral therefore no grounding rod for generator and remove the generator bonding jumper ?
Do I have that right ?
A lot of info to take in, but it's super important to get right, thanks for making the vid...subbed
My generator show two phases on line and neutral. I can't connect it to inverter charger. Any solution?
hi all, my portable inverter generator (which is not to be connected to house as we're offgrid) has a port for grounding cable. Is this to be used only if hooking up to a house mains panel/socket? if I use as stand alone, to power tools and drive a sub pump, do I need to attach a grounding wire/rod to my genny? thanks
This may seem like a silly question with an obvious answer, but would it be correct to say that a "ground-neutral plug" is simply a way to turn your generator into a "bonded" generator? Essentially accomplishing what your jumper does? Or is it something different and/or does something more? (Bonus question: And why would you NOT want to have a bonded generator?)
Just came across your video today you seem to have a grasp like no other on the issues of grounding and bonding. GREAT JOB!! Can you please help me with this scenario as to if, I’m on the right track or not. I’ve already asked 3 local electricians and they all gave me conflicting information. I have a 50-amp interlock breaker on my panel and a generator socket outside of my house for bad weather outages. I just purchased TWO (Harbor Freight), Predator 5000 W inverter generators @120v. I naïvely thought that adding them together with a parallel kit, sold by the same company would boost me up to 240 V and 10,000 W. I know now that’s not reality because, there are only 2 wire connections on that generator and the 240 V generator has 3. So I was thinking to build a combiner circuit so then each leg would be 5000 watts at 240 V. Here’s what I was planning, take a 30 amp, 120v plug out of each generator and connect them in a box with a 50-amp socket, tie together the neutrals and place them in their terminal position, combine the grounds place them in their terminal position, and lines 1 and 2 would go each in their opposite terminal locations. Will this work it seemed straightforward to me until I thought, would the 2 phases from 2 different generators clashing with each other? I thought of this because I saw a video about power plants needing to precisely spin up their generators to work with each other’s sine wave. Is this not an issue with inverter generators or in my scenario?
Kind regards,
Best explanation I've heard hands down! Thanks!
Thanks Robert. I think I get most of this, but I still have a question that I don't believe you covered. Does your " Do I need to Ground My Generator" slide apply when feeding an old 3 wire service house with a modern 4 wire generator?
So if my RV is not bonded inside the power box do I need to bond the generator??
Extremely thorough but Please maybe I missed it and I’m getting conflicting info from different sources including n manufacturers.
My generator is neutrally grounded but is going to be hooked up w a 50 amp inlet plug on my home to the 50 amp breaker in my main with an interlock device. So in this direct connection I Do need a ground rod attached to generator ? And if so do I disconnect the neutral bond wire on the alternator?
Thanks in advance. Just trying to get some clarification
If I want to back feed my shop that is fed via a 125A panel from a 3ph service without a master disconnect, can I interlock the feed breaker at the shop panel to a generator inlet breaker? Subpanel G and N are not bonded, so would generator need to remain bonded or does N at subpanel need to be transferred as well?
Great video. What if I'm backfeeding my house panel and I don't have a ground in my cord? Just 3 wires, 2 hots and a neutral. Is it OK to have the generator bonded?
If you're using your generator to charge/run your holiday trailer I would think you would want your generator neutral to be bonded as the neutrals and grounds would be separated in your main panel of your trailer.
I would also think that if your trailer is connected to shore power the main power coming in would have the first point of disconnect so the grounds and neutrals are bonded together.
Are my assumptions correct?
Also when using the generator to charge the trailer and run extion cords ahould I install a ground rod for that application?
I have a question. So if you dont have utility power grid connected to a farm house and in your example replace the utility with an inverter. So with two power sources (generator and solar inverter system with a battery backup).
My question with refference to a transferswitch that also switches neutral wire- here in your example you basically have two power sources's neutral wires connected with each other through a ground wire... does this not have potential bad effect? So the neutral wires of two power sources touch each other and both sources are generating potential but only one feeds a load - does this not pose any danger to the equipment?
If my gen was close enough and it is bonded when i break the neutral at transfer i have to have a ground rod could i use the one that the house is on since its broken att the transfer to keep me from putting another rod in the ground
SOMEONE PLEASE HELP! I have a bonded generator that I will be connecting to a mobile home. The first disconnect is outside by the meter. I'll be connecting to the subpanel inside, using an interlock. Will the main panel outside provide the bonded neutral, or should the generator be bonded? And with that setup, do I need a grounding rod? Thanks
Neutral to ground Bond is to occur only one time in the system.
Based on this information...I do not have a "switched neutral"...but I want to be sure. My electrician installed a twist-lock 30 amp box on the house next to my outside panel, ran 8-3 with ground to my outside panel....connected the two hot leads from the box to a 40 amp breaker inside the panel..and ran the neutral wire to the neutral bus bar and the ground to the ground bus bar. I can see that inside the panel the two bus bars are bonded, and I have a mechanical interlock preventing the main breaker from being on when the new 40 amp breaker is on. So I assume that I do NOT have a switched neutral set-up...(and that when power is out and main is switched off and locked) that I should run a "floating neutral generator" when plugged into that box, and that I don't need a ground rod. Am I correct in this? Thank you for a reply.
First of all, the 40 amp breaker is a code violation. The over current protection rating cannot exceed the rating of a single receptacle even though your 8-3 wire is oversized.
You do not have any neutral switching since you have no transfer switch.
Your ground and neutral bond at the generator needs to be separated and the neutral wire insulated.
Install the ground rod and connect it to the frame of the generator or to the same terminal where you removed the neutral. Either way, use a proper set screw lug.
@@trustme7731 You are saying that the 40 amp breaker exceeds the rating of the 30 amp box and thus is a code violation...correct? I wondered about that.
@@spacecoastz4026 The breaker exceeds the rating of the 30 amp receptacle. That's not allowed for a single receptacle. In a perfect world the 30 amp generator breaker would protect it but who knows if it would fail or how this would be used by someone else.
@@trustme7731 Understood...thanks
great video ... how does the bonded and un bonded work when you have GFCI on generator ....or a motorhome with built in generator are they unbonded with GFCI plugs ?
What about a generator connected to a house via an inlet box directly to a breaker? That is to say no transfer switch.
Does the generator need to be bonded and/or grounded? Thanks.
Hey thanks for the great video. Question: I have a 30amp single phase RV. I installed an automatic transfer switch so I can use an inverter, a generator, and shore power all separately and seamlessly. The transfer switch switches both the hot and the neutral leads… this way, I can use shore power when I’m home (that’s bonded at the panel) and a bonded generator, when I’m camping off-grid, and I can use my inverter when the generator isn’t running. My question is this- should I tie a ground wire from my inverter to the chassis of the Camper trailer? (The inverter has an external earth symbol with a screw for mounting a wire- but my sense is not to use this connection unless using the inverter in a house application). Also, interestingly, when I test the inverter with a meter, it only reads as a bonded ground when it’s turned on.. when it’s turned off, it reads as a floating neutral.
as I recall, in most RVs everything is floating till you plug into shore power, where the ground pin does the rest with the utility connection. Since it's a 120 volt system complete isolation can only take place if they disconnect the neutral. The answer for your inverter should be in the owner's manual, or available from the mfgr's tech support. They have the final word.
What about static electricity generated on the generator itself using the ubiquitous manual interlock with the neutral bonded to the ground at the panel. Still recommend no grounding rod at the generator? I think that static would be dissipated on the main panel grounding rod, correct? This is it awesome video. Thanks.
So, I'm using an interlock kit to connect my 12kw portable generator to my house. Am I correct to assume that, functionally speaking, this is electrically the same as your transfer switch with a fixed (non-switched) neutral? In which case, I should be unbondinding the neutral and ground at my generator, but NOT using a ground rod at the generator? Correct?
Yes, the interlock kit is the same as the 2 pole (unswitched neutral) transfer switch. Also, floating neutral and no ground rod.
Old school wiring in the house. No three prong plug. Just neutral and hot. If a grounded generator is added when the local current is off, will it ground the house or go on as the same as it ever was? (No ground in the house.)
Your electrical system is what it is. The generator will not change it.
So quick question ... I have a circuit breaker box with 2 hots and 1 connection for either ground or Neutral there is a bar on both sides of the box that IS connected to each other SO my question is what do I do with the ground and neutral wires coming into the box with only one connection? do I twist the neutral and ground wires together and connect them to the LUG? The wires coming in are from a generator but there are 4 wires coming in and only three Lug screws in my box
This question can not be answered with information given. Not enough detail. Sounds like the panel is fed by a generator only, but nothing about how it is used and connected to what.
One of the clearest explanations I have seen. Thanks!
I just hooked my shop up to a transfer switch and when I connected my generator all of the GFCI breakers popped and cannot be reset. Is this because of a double bonding situation?
Thanks for the explanation.. would be interested in how all of this works with powering an RV system.
I have had a generator since 2003. I have never used it as a source for my high-efficiency gas furnace for fear that it would take out the $$$$$ control board. I was told that the generator puts out "dirty" voltage. More recently, I've read the problem is the ground and that the flame sensor will not see the spark ignite the flame and will shut down. How do I get a plane jane Generac generator to power my furnace. OBTW, there are videos out showing that expensive Honda generators, with floating ground, will not power up the furnace. My microwave will not run off of my generator either. I am using an extended version of the twist lock on the generator going to 4 each 120VAC outlets. Thanks.
Why do you show the neutral-ground bond at a service disconnect switch which is not part of the breaker panel? The vast majority of residential services have the neutral-ground bond in the breaker panel because the main breaker in the panel is the first point of disconnect. I'm sure such systems exist, but every residential panel I've worked on has the L1,L2,N service wires coming from the utility transformer to the meter (which is not a disconnect) and then to the main house panel, and the main breaker in that panel only disconnects L1 and L2. In this scenario it would not matter whether the transfer switch disconnects the neutral or not, you'd still need an unbonded generator.
Why do you need a ground rod at the generator though when you use a switched neutral transfer switch? the neutral is no longer shared, but the PE (ground wire) is still shared with the house, wouldn't it just use the grounding rod that the house uses by default?
Excellent video you made it EZ to understand thank you
so with my bonded generator.. going to use as home only..house is bonded...im good to unbond the ground off the generator right.
It's not always possible without disassembling more than you want to. If you can do it, I suggest you add a warning label to the generator making it clear to never use it unless it's feeding a grounded building that already has the proper bond.
correct. Generator should be floating neutral (unbonded). Get a bond plug if you want to use the generator with extension cords.
watched your video, I am setting up a bonded generator to a house with a interlock. someone told be to run a grounding wire from the generator to the same grounding rod used by the house, can you give me your opinion, i just want to be safe with generator and and not endanger any thing in the house, thanks
If you're using a 2 pole interlock kit (with unswitched neutral), you'll need to remove the bonding jumper in the generator and do not add a ground wire (or attach) to the ground rod .
Maybe I missed it but I have an Interlock Switch to change from utility service to my generator inside my breaker box. The 50 amp receptacle that the generator plugs into to provide power to the breaker box is grounded to the same ground rod as the breaker box and the meter coming from the street. So the breaker box is grounded whether power is coming from the street or from the generator. I’m confused now if I need to also add a grounding rod connected only to the generator.
Someone else asked the same question above, and spacecoastz gave the following excellent answer which I believe is correct:
Here is an answer I found from Home Battery Bank in reference to an interlock system. I found it down below.
"When properly installed, an interlock just makes it so that you can't have the mains power turned on while you're turning on the breaker that you're using to backfeed the house with your generator. The power line crews appreciate it! The neutral is left intact (and the house is already bonded) and the generator still shares it with the house. The generator should be floating neutral (unbonded) so that you don't have parallel paths for the return current (and any fault currents) back to the source (the generator). Of course, I recommend reaching out to your local certified electrician before you make any changes."
You need to have a floating neutral generator and no additional ground rod
@@kipster-ll6po my electrician verified that no additional ground rod was needed in my setup. Thanks
Thank you thank you thank you have internally grounded portable generator with a bonded neutral The guys that set up all of the cabling for a three-phase 120 208 system put in grounding rods in addition to bonding the three generators to themselves getting a reading from hot to ground of 120. Suspect that ground rods are not applicable or advised. Now I'll take this information and do more research but I think I've come to the conclusion that grounding rods should not be used on internally bonded isolated generators not attached to a house system. The only advantage is during a lightning strike from what I've learned from your video
Thanks for the great explanation on bonding and ground rods.
Really thorough lesson.. Very effective pictures easy to understand Thank you 😊
So basically, if I'm using my generator to input to interlock into my electrical box, the generator should have a floating neutral since ground and neutral are already bonded inside my breaker box. If I'm using generator just with extension cords, then it should be bonded. correct?
correct. Get a bond plug to make it easy.
Can I still use the rest of the plugs on the generator with the set up you have at time 1500
Sounds dumb I know but....define "extension cord" in the context used here? ANY cord plugged into the generator or do you mean a suicide cord with male ends on both ends?
Very informative. I've watched this few times now and trying to relate it to my scenario to figure out how to wire things up safely. I have a generator that I will use to power my completely off pole shed. I'm planning to use 30 amp inlet wired into small sub-panel or main panel to power a few outlet (GFCI) and some lights. My question is where should I bond? Should I bond at generator or should I bond at panel (not connected to utility power)? Does it matter? I'm thinking I would want to bond at source, the generator, therefore keep grounds and neutrals separated at panel. But I'm not sure if that is right or not.. Still wrapping my head around it. Thanks.
I am trying to do this very same thing as you..did you find any answers for this? Lol..I’m thinking it NEEDS bonded at our panel bc that’s how it is in our homes and the transformers are ground neutral bonded and that would be like our generator(assuming the generator we have is bonded by manufacture
@@jeremysmothers5143 No. Unfortunately I have not been able to get straight answer to this question. I'm on several electrical forums and seems no one either knows or wants to tack this question. So I called a master electrician and he never called me back.
nice video, I have a question. I have a battery bank and I'm 90% off-grid I only use city power for powering up air-conditioners, the thing is my neutral (inverter) is bounded with the city power neutral which is bound at the main panel with their ground, should I isolate and install a ground rod and only switch to city neutral & ground when I'm using them? I don't live in the USA and the grounding practices here are less common.
so this is not a question about regulations, but best practices.
lets say my unbonded generator without a ground rod one of the 120volts generator leeds comes in contact with the generator frame what then?
So do I need to unbond my generator when
Plugged into breaker panel with a interlock
yes
Hi, thank you so much for the explanation. For a typical floating neutral generator and used with extension cords, will a grounding plug (making connection between neutral and ground), make it safer? What is your opinion on that? Thanks.
He already explained it at 10:00. Keep the generator floating neutral (don't bond neutral to ground at generator). Neutral is bonded to ground at the main panel.
@@urbanturbine thanks for the feedback. I was specifically asking for the case with extension cord. You are referring the case when the generator is hooked up to the house panel which makes sense to use the connection at the house and not have another neutral to ground bonding at the generator. I am wondering when an extension cord is used, whether a Ground to neutral plug should be used to at least get some protection from any hot to ground fault on any appliance with metal exterior.
@@bennettonline absolutely you can bond the generator with a grounding plug... just be sure to remove the grounding plug if you connect the generator to a typical transfer switch that does not switch the neutrals...
Hi could someone clarify for me when he says using an extension lead, would the toasters own lead with out an additional extension lead connected making it longer be safe connected directly to the generator? I'm assuming not, if it got a fault its the same right (toaster plugged directly into gen or with additional extension lead) I guess he says extension lead referring to when it's not hooked up to the house via switches. This really has me confused can someone help me understand. Thanks
Yep. When he's speaking of extension cords that is when you're just running cords from the generator's onboard plugs to certain things in the house but not connecting it to the home's wired electric system.
Home Battery Bank, my generator is neutral bonded to frame. I’m using an interlock with 30 amp 240V(L14-30R). I will consult a local electrician but was looking for your thoughts as well. I can very easily convert to floating neutral if that makes the situation better. Thanks,
it all depends on what king of transfer switch you have... if you have a typical transfer switch that only switches the hots, then you do NOT want it bonded at the generator... if you have a transfer switch that switches both the hots and the neutrals at the main panel - then you want the generator bonded AND you want to connect the generator to a ground rod... that's why hot/neutral transfer switches are not typical...
Good explanation.
How about the situation where you are feeding a transfer switch with the 240 outlet from the gen and using an extension cord from one of the 120v outlets to power another appliance that is not on the gen transfer switch? Is it ok to have the gen be a floating neutral even when using the extension cord?
I'm no expert, but I would say yes. it's ok, since the neutral and ground are connected to the main service thru the extension cord, thru the generator, and back to the house. This is assuming you have a "hots only" transfer switch.
@@aspensulphateYeah. Basically the neutral should only be attached to the ground once. If the transfer switch doesn't disconnect the neutrals when transferring the the generator is always connected to the neutral of the building and the neutral of the building is always connected to its ground rod/plate.
I’m hoping you can clear up some confusion I have regarding generator protection devices and bonding. Specifically, I view circuit breakers as over-current devices which trip when their rated current is exceeded. Then there are GFI devices which I like to think of as differential current devices in the sense that they trip when the outflowing current on the hot wire does not equal the return current on the neutral wire. Can you elaborate as to how bonding effects each (or both?) of these devices? - Thanks! - Jim
Your understanding of both is correct. GFI requires No equipment ground to operate. Circuit breakers or fuses (overcurrent protective devices) have two functions. First, overcurrent (as you stated). Second, short circuit. The part that may be missing is the current path from a ground fault. Let’s say your hot in your electric heater, touches the metal case. Let’s start just past the circuit breaker at the lug. The path of current is, hot conductor to case. Case to equipment ground. Equipment ground to panel bus bar where both connected. Neutral to utility transformer. Utility transformer to panel power bus bar. Bus bar to breaker. Thousands of amps, magnetically trips the breaker. Hope this helps. Respectfully, Kevin
@@KevinCoop1 : Thank you, Kevin!
Is grounding to a copper water supply line (coming out of house for sprinkler system) an acceptable alternative to a grounding rod for my generator? It’s the same piping that my breaker panel is grounded to about 20’ ft upstream from this point.
a copper water pipe generally sufficed for a grounding rod years ago - but code now generally states that if you use a copper pipe for a ground rod, you also need a regular ground-rod sunk in the ground at least 6 feet away from the copper pipe (the further away the better)... in fact most electricians will now routinely sink two ground-rods to ground a panel... since you're connecting your generator to a ground rod - I assume your generator is bonded and you are also connecting your generator to your house through a hot/neutral transfer switch (where the neutral is also switched, which is not a common type transfer switch)...
I have a Champion inverter generator (4500/3500) with a floating neutral. I will be using a Reliance "through the wall" receptacle that is NOT grounded - it just splits a 120V 30 amp plug into standard wall plugs (6) through the wall into the interior of the house. Extension cords would be plugged into appliances and a portable A/C. Do I need to GROUND the generator using a grounding rod?
1. How do you know its a floating neutral? Portable generators come bonded. Test for continuity at the generator between a receptacle ground terminal and its neutral terminal.
2. I have no idea what a "through the wall receptacle" is.
3. If you are using cords from the generator receptacles to each individual piece of equipment in the house, then the generator ground and neutral must be bonded and no ground rod needed.
In summary:
- If the transfer switch *doesn't switch* the neutrals, you *must not* _(i.e._ are not allowed to) bond the generator neutral to the generator ground, and you *are not required* (but are permitted) to ground the generator.
- If the transfer switch *does switch* the neutrals, you *must* _(i.e._ are required to) bond the generator neutral to the generator ground, and you *must* _(i.e._ are required to) to ground the generator.
Right?
You are right
be aware that sometimes the NEC rules may not be applicable. To wit:
The National Electrical Safety Code (NESC) is a set of safety standards that govern the installation, operation, and maintenance of electric supply, communication lines, and related equipment. Contact your local utility before attaching any alternate source of energy in lieu of a utility transformer to your structure, they usually respond free of charge.....
To avoid electrocution with a fault present, I would rather not complete a circuit with a floating neutral generator than rely on a CB to pop in time in a bonded neutral generator. If I want to know if a fault is present (hot metal skin), then I can use a NCVT tester.
Most people who bond their neutral to ground in a floating neutral generator are RV owners using surge protectors. For them, more about getting their surge protectors to work than an electrocution issue.
I'm thinking that the setup where the generator hooks up to directly to the neutral in the service could be problematic since the very reason for the outage could be a fault in that very neutral/ground!
That is the way 99% of generators are connected. And it is safe.
If you convert a portable generator to a floating neutral, should you not use the outlets on the generator at the same time the generator is energizing the house through the house electrical panel? I'm wondering, since a neighbor has expressed interest in running an extension cord to the generator.
I don't see why you couldn't use those outlets since the neutral is bonded at the house and essentially they are no different than an outlet in your house. If you're talking about that neighbor connecting into your generator, I'd be more concerned about them exceeding the output of your generator and tripping your generator breaker.
Thanks for the clear explanation:) The visuals really helped
3:39 if the neutral is not grounded then neither wire has potential compared to the ground so you can get shocked only between the wires, not between any wire and the ground so the fault would no cause any risk.
Newbie here. I use nothing but electrical chords to run some key items (freezer, etc) during a power outage. Per this video, I should bond my neutral. I'm not using the L5-30r socket on my generator (120v only generator, no 240v). Can I purchase a L5-30p plug and do the bonding within the plug? I makes for simple conversation back and forth between floating and bonded.
Get a bonding plug they are inexpensive on Amazon. It will plug into a 120 receptacle on the generator and the entire generator will be bonded including the 30 amp receptacle
Check your generator to see if its already bonded. See if there is continuity between the neutral socket opening (the wide one) and the round ground opening socket, using a meter. I had to move my meter leads around some before I made a good connection and found that I have a bonded generator.
Would an interlock switch be essentially the same scenario as the normal transfer switch? Meaning you want a floating neutral and no ground rod?
I'm wondering the same
@@brandonmurphy4657 see the comment from bradsmith5131 a few comments down. I have the same question and it appears that the generator needs to be floating neutral and no ground rod in the case of the interlock from what I am seeing.....
correct. unbonded and no ground rod.
Can you do one when you use an interlock? The generator I have says it is neutral bonded to ground.
When properly installed, an interlock just makes it so that you can't have the mains power turned on while you're turning on the breaker that you're using to backfeed the house with your generator. The power line crews appreciate it! The neutral is left intact (and the house is already bonded) and the generator still shares it with the house. The generator should be floating neutral (unbonded) so that you don't have parallel paths for the return current (and any fault currents) back to the source (the generator). Of course, I recommend reaching out to your local certified electrician before you make any changes.
The gfci will trip on a floating generator
I don't have my generator on a 'frame', I have it on a steel metal garden cart, because it's easier for me to move, it's very heavy. Since the cart has for rubber wheels, would it be advisable to put a grounding rod in to attach to the cart? I used this generator last year here in East Texas when they froze us out for 3 days, had no problems, but what you have said about the frame being the ground for the generator now has me a bit worried. Thank you.
If you have a 4 wire connection to the house, you are already grounded through the home system.
@@rupe53 ; thank you, I knew that it was, but I just run a cord through the window, I am not able to connect it directly to the electrical fuse box...
@@moneypenni1694 ... if you are not tied to the house electrical system then you do not need a ground rod.
@@rupe53 ; sorry for the tardy reply, pc issues...sigh. Thank you for your response, I appreciate it, we're supposed to get slammed tonight with thunderstorms.
So my solar generator is a floating neutral and my transfer switch is Generac HomeLink, which switches the neutral from the grid neutral. The only thing shared in the transfer switch is the ground bar which is connected for both power sources. I would assume that if I used a generator grounding plug that bonds the neutral and the ground together on my solar generator this would meet the requirement to bond my solar generator when powering part of my home and gives it access to the homes' existing grounding system, which includes the grounding rod, yes? Thank you for this great video!
I would say you can test this with a meter. Flip your transfer switch to the standby power mode and see if ground and neutral are still tied together, measured at the plug where you connect your generator.
I have three main panels (2ea-200 amp, 1ea-100 amp) with individual meters ( 3 separate electric bills) feeding house, shop and well pump . All power from the power company is fed from one 35KW transformer.
I have a 15 KW PTO (tractor powered) backup generator.
I have a 125-amp sub-panel located near the generator. The sub-panel has 4 ea 50-amp double pole breakers. One breaker will be the input from the generator to the sub-panel.
The three remaining breakers in the sub-panel will each be connected via a 50 amp breaker feeding power to the main panels for the house, shop, and well pump. The main panels will each receive a new 50-amp breaker and an interlock switch.
The sub-panel and three main panels are connected with four conductor, 4awg underground aluminum wire.
Each of the three main panels has its own interlock switch with a 50-amp double pole breaker. When in backup power mode each main panel will be powered by the generator through the sub panel if the 50 amp breaker in the sub-panel is on for the targeted main and the targeted main panel is in backup power mode via the interlock.
My questions: how do I connect the neutral and ground from the generator to the main panels? I assume the generator neutral should be floating. Do I even need the ground wire from the generator to the main panels? does the generator need its own ground rod?
Thanks for the help. I have ask several electrical engineers and gotten different opinions.
If “All” your three main panels are correctly installed (with bonding from N-G at each system), then there is no disconnecting that neutral. Therefore, you do not want a N-G in your generator. Also, what you are calling your sub panel, is a generator distribution panel. It receives no voltage or current from the main panels. Just my opinion.
Great work explaining this!
If the neutral is connected using the neutral from the power company and the generator, would that not backfeed the grid? Aren't you technically trying to return the electricity back to the power company?
No, not via the utility neutral. You can only backfeed by completing a circuit with the utility ... meaning between the two utility legs or between the utility neutral and one leg. The neutral alone has no ability to backfeed anything. It just equalizes the potential of the neutral conductor on the utility transformer. No current actually flows.
@@junkerzn7312 Got it! Thanks! That makes sense.
Very well explained, thanks!!
This was super helpful, thank you!
Great explanation, thank you.
What about for a bonded to frame generator plugging into an interlock?
What about it? Is the neutral being switched? That's the question you need to answer, and you need to act accordingly per the information in the video.
@@chris2790 good job explaining nothing... 👏
@@dthompsont3796 it's in the video.
Check the comment above from bradsmith5131 concerning this issue. The generator needs to be converted to floating neutral with no ground rod if you're just using the interlock in your main panel. Many people confuse the simple interlock system with the more complicated transfer switch and it wasn't directly addressed in this video.
Awesome video. Thank you!
Thanks for the video
Got it, finally! (answer to my question at least) Thanks!
nice simple explanation
Excellent video.
I always leave my generator bonded, because I've seen firsthand what damage happens to appliances in a home, if the neutral connection is suddenly lost.
That bonding should only occur once. At the first overcurrent device. Bonding in the generator does not help with your concern.
I just bought a 12,000 watt portable generator. In the instructions it said that you need to use a ground otherwise you may get electrocuted. Then I realize that they didn't include a ground with the new generator LOL. Seems like they should include something simple and cheap that can save your life, just a simple rod and wire.
My generator said the same. Not only did it not include the ground, zero instruction on how to install it. Seems like a liability.
Probably just trying to cover themselves. I have found many places do not have a good ground. Ground rods are not cheap. They are thick, and if memory serves me correctly, must go below the frost line and/or reach a certain moisture level in the soil. Good thing to look up before you install one.😁
Read carefully. The word ground can be misleading. Is it saying or showing equipment ground, or grounding electrode conductor? Two totally different things. Be careful!
An easy way to tell if the generator neutral is already bonded is to use a continuity tester and check between the neutral and ground on one of the generator receptacles. If you have continuity, then you don't need a ground rod for standalone use.
@@paulnandico2370this makes sense but what if you are located on rock for god only knows how deep like me ?