Will a Metal Box Alone Provide a Ground for Electrical Wiring?
ฝัง
- เผยแพร่เมื่อ 26 ธ.ค. 2024
- Amazon Prime Student 6 month Free Trial: amzn.to/2J4txZw
UNLIMITED ACCESS TO 75 MILLION SONGS
Free for 30 days. Cancel anytime: Amazon: amzn.to/35IlgC6
Fluke 117 Electricians True RMS Multimeter: Amazon: amzn.to/2MAmA0Y
Wago 221 Lever-Nut Assortment Pocket Pack: Amazon: amzn.to/2NdPPcH
Wago (100) 221-412 (50) 221-413 (25) 221-415 Lever-Nut Assortment Pack: Amazon: amzn.to/2NHbE3U
Wago 221-412 2-Conductor Compact Splicing Connectors (Pack of 100): Amazon: amzn.to/2QpcIYF
Wago 221-613 Lever-Nuts 10AWG 3 Conductor Compact Wire Connectors 30 PK: Amazon: amzn.to/2x9lEcI
Wago 221-415 LEVER-NUTS 5 Conductor Compact Connectors 50 PK: Amazon: amzn.to/2xjvA2e
IDEAL Grounding Pigtails with Ground Screws (Pack of 50): Amazon: amzn.to/2REz8pa
IDEAL 61-534 Digital Circuit Breaker Finder with Digital Receiver and GFCI Circuit Tester: Amazon.com: amzn.to/2ql9yYz
Knipex Tools 13 88 8 US Electrical Installation Pliers: Amazon: amzn.to/2H2rxxm
IDEAL Industries 61-164 SureTest Circuit Analyzer: Amazon: amzn.to/2Da3TwM
Ideal Industries 61-183 Alligator Clip Adapter for SureTest Circuit Analyzers: Amazon: amzn.to/2PjywVn
Ideal 35-9305 Insulated Screwdriver Kit, 2 Piece: Amazon: amzn.to/2VIu2Nx
Klein Tools 33532-INS Electrical Insulated Screwdriver Set of 2, 4-Inch Phillips andCabinet Set, Made in USA: Amazon: amzn.to/2H2fyjp
Veto TECH OT-MC Veto COMPACT Open Top Tool Bag: Amazon.com: amzn.to/2rgC00e
Discount on Amazon Prime: amzn.to/37ZJmLN
Amazon Business Account: amzn.to/31NGgGw
Amazon Kids+ : amzn.to/2J6xFIt
Exclusive benefits on Twitch: amzn.to/2HCWNpN
Amazon Music Unlimited Free Trial: amzn.to/35IlgC6
Amazon Home Services: amzn.to/3jxIFez
Kindle Membership Plans: amzn.to/31O9Pro
Amazon Prime 30 Day Free Trial: amzn.to/3mqTcdq
Amazon Prime as a Gift: amzn.to/3jxxF0U
Create an Amazon Wedding Registry: amzn.to/3jyHL1m
Audible Gift Membership: amzn.to/31Oxb08
Prime Video Channel Free Trial: amzn.to/3mwgUEW
Prime Student 6 month Trial: amzn.to/2J4txZw
Create an Amazon Baby Registry: amzn.to/35CGa5K
The original Sparky Channel was hacked in January of 2020 and I lost 934 videos, 182,000 subscribers and 65 million views. So I started over. This Sparky Channel is new and has a different URL than the original. If you were a subscriber to the original Sparky Channel your subscription was taken away from you without your permission due to the hacking. You can remedy this by subscribing to this new Sparky Channel. Thanks so much for your understanding on this matter!
The video was taken with the: PANASONIC LUMIX GH5 Body 4K Mirrorless Camera, 20.3 Megapixels, Dual I.S. 2.0, 4K 422 10-bit, Full Size HDMI Out, 3 Inch Touch LCD, DC-GH5KBODY (USA Black): Amazon: amzn.to/2VvWVcV and the PANASONIC LUMIX Professional 8-18mm Camera Lens, G LEICA DG VARIO-ELMARIT, F2.8-4.0 ASPH, Mirrorless Micro Four Thirds, H-E08018 (Black): Amazon: amzn.to/2Yem0JO
Saramonic UwMic9 96-Channel Omnidirectional UHF Wireless Lavalier Microphone System Two Transmitters and One Receiver for Nikon Canon Sony DSLR Cameras, for Video, Field Recording,Interview, ENG, TV: Amazon: amzn.to/2Kc5qWe
This video was edited with: Cyberlink PowerDirector 18 and PhotoDirector 11 Ultra: Amazon: amzn.to/2Qz2w1t
To make this video I used the ZoMei Z818 Light Weight Heavy Duty Portable Magnesium Aluminium Travel Tripod: Amazon.com: amzn.to/1XOgA5T
This video was made using the: Transcend 64GB Class 10 SDXC Flash Memory Card (TS64GSDXC10E): amzn.to/1w02Oxn
Bill and sparkychannel.com are participants in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com
THANK YOU FOR THE INFO BRO 👌✌🏼👍🏼
No problem, thanks! 👍
@@SparkyChannel
I just want you to know that I was unsubscribed from your channel and thought you stopped making videos over a month ago. I only looked you up today because it crossed my mind and I was worried about you.
Your channel is nothing but good info and that should never happen! I resubbed and checked the bell for all videos!
@@skeetorkiftwon Welcome back to Sparky Channel! Thanks so much!
No, the reason you're getting 5.4 volts is due to something called, "Capacitive coupling". The impedance of the meter is very high, and there is a small amount of capacitance between that black lead and lower-potential things near it (you, the wood, grounded conductors, moisture in the air, etc.).
Put a 2 watt incandescent light bulb in parallel with those meter leads and you'll notice near zero volts, because the impedance of that bulb will be very low, putting a comparatively large load on the circuit, effectively shunting that minute amount of capacitively induced current to a much greater impedance, causing the voltage to drop to near nil.
Good basic stuff. Always love to hear about the stray voltage or the hot to "air" voltage.
Thanks! Have a great weekend!
Thanks for the video! Thanks, too, for the endorsement of Wago 221s! Those things make life soooo much easier!
Code was a strange thing back in the day. Seen all kinds of weird attempts on metal box grounding. Good straight forward explanation Bill. Have a nice day👍
Yes, I have as well. Thanks and have a great day!
To clarify for Joes/DIY:
"Grounding" is connecting a ground wire to receptacles and switches, "bonding" is connecting a ground wire to metal gang boxes. If your house was built after 1967 then the metal gang box should be bonded, the 1968 NEC code required all receptacles in dwellings to be grounded.
Love Sparkman always teaching us safety first! He is the best on TH-cam! Thank you Sparkman for another practical teaching video!
Thanks so much Joe!
Great demonstration! I would have liked it even more if you had added medal conduit connected to a bonded versus non bonded panel.
Good video Sparky. Grounding and bonding have come along way.
Yes, it was very different in 1960! LOL!
Very clear explanation and helps to further our understanding of what ground properly means (a metal box may or may NOT be grounded itself). Thanks for a super helpful video
Simple answer: a metal surface is not a ground unless and until you bond it to ground. (which does take some thought when dealing with something more than a simple plate. i.e. the door to a cabinet needs a _wire_ to keep it grounded, the hinge doesn't make a perfect electrical connection.)
Is it possible for the outlet tester to show grounded while still being barely grounded like the second box if you install a three prong outlet over it?
You were extremely helpful. God bless America.
Always helpful, Thanks sparky!
Hi White Tiger! I hope you are doing well! No problem, thanks!
A meter reading of 120v between the black wire and metal box DOES NOT prove that there is a good ground connection to the box. There could be excessive resistance in series because of a poor connection or damaged ground conductor. The voltage lost across the unwanted series resistance will not show up as a noticeable voltage loss at the meter because the meter resistance is very high and draws a very small amount of current.
The only way to determine with the meter whether the box ground is good or bad is to make a resistance measurement between the box and the neutral wire. The resistance should be very low, under one ohm assuming the box isn't very far from the panel.
WHAT?
If you have a tester and you touch the hot with one lead and touch the box with the other lead and it shows 120 -
you've got a connection.
@@frankpaya690 Correct. But it could be a BAD connection otherwise known as a high resistance connection.
It provides no ground at all, there will be no current flowing in case of a fault. It will just sit there, live at mains voltage, until someone comes by, touches it and get an electric shock. The reason for the displayed voltage is the high internal resistance of the DMM. The target is to get a low impedant connection, so in case of a fault the circuit breaker or the GFCI will trip or a fuse will blow and preventing that live parts are touchable. The circuit breakers and fuses require a low Zs (Z is impedance, and the s means ground loop) because they require a high current to trip. GFCI will trip on a low current, but a low Zs is still desirable. Installation testers, which are quite common in Europe and now swap over to the US, can measure the ground-loop impedance and calculate the PSSC (prospective short circuit current). The electrician then must look and decide if the PSSC is high enough to trip the circuit breaker within the time limit. GFCI will help too in that case, especially if you don't have a TN-C-S grid (in the US commonly known as MGN), and got a TT grid instead (neutral is not grounded in the customer installation, the grounding system is only provided by local earth electrodes which have a high resistance, depending on the ground where they are installed in).
Even if the old wires are smaller, they're better than nothing. And they'll only carry a current in a fault situation, and that only for a fraction of a second. A GFCI shall trip in less than 0.2s, in most cases they'll actually trip between 0.02 and 0.03s. No chance of overloading the wires. A short-circuit must be switched off (fuse protection 32A or less), according to german regulations, in less than 0.4s in a TN-grid (if you don't have a GFCI protected circuit) and in less than 0.2s in a TT-grid (that's actually only possible with additional GFCI-protection).
Thanks Marcel!
What if the metal box is grounded via metal conduit...so the metal conduit connects back to the panel that is grounded (at least I assume that's how that works). But is that essentially the same and you can then ground to the metal box if need be?
Yes. Where I live, we can't use Romex. Only EMT, IMC, RMC, and various flex cable is allowed. One just needs to make sure all connectors are well torqued so they don't get loose over time due to heat, vibration, etc. There are a bunch of rules in the NEC (and local) for AC (BX, etc.) related to this.
Good info. I didn’t know about the grounds on old houses possibly being attached on the back of the metal box. It does look like 16 or 18 gauge wire in the video. Not code compliant today.
Well that answered why I was getting a low (~5v) reading when trouble shooting an old metal box but it does bring me to a how to fix question. I have a metal box that doesn't appear to ground properly off the metal conduit. If I run a ground wire to the back of the box (which I can do easily given its location close to the breaker box) and then ground the outlet to the box is that code? I know running said ground wire directly to the outlet isn't but isn't this alternative just a cheat on the code? right now I'm just using a two prong but thinking alternatively replace with a GFI (and the "no equipment ground" sticker).
Hey Sparky! How do you ground an old house?
My old light switch had only 2 inputs for hot and neutral but the wire itself has the ground screwed into the metal box. On my new switch i wired it with just the hot and neutral so the ground screw on the switch was left without anything.. I assume the wire grounded to the box eliminates having to run the ground to the switch ?
Im guessing since the ground wire is grounded to the box and thr switch is screwed to the box it should be grounded at that point
Thanks for sharing your knowledge.
My pleasure!
Great I been waiting for a tutorial like this one can I check each receptacle in the house because I have only two conductors and no ground I'm so afraid to add a green pigtails inside of the receptacle since I'm replacing the old receptacle 15 amps.
Please respond thank you Sparky
You might consider making a video on how does grounding the metal box improve safety since that was not included in this video.
While I am not disagreeing with anything you said about box installations and grounding, I feel it is important to note something.
A measurement of potential (voltage) does not necessarily guarantee the current carrying capability of that pathway. In other words, you will measure the same 120 volt potential across 4/0 cable as you would across 14 ga. but the current carrying capabilities are far different.
The ground path must be robust enough to handle the current delivered during a short-to-ground occurance. For instance, if you grounded a 100 or 200 amp service main panel to your water main with a 12 ga. conductor, you'd measure a 120 volt potential from any leg to that ground but that would in no way be suitable to carry any large amount of current. If you shorted one of those main legs or bus bar to ground, that 12 gauge conductor would melt almost instantly. The ground path must be robust enough to at least briefly support current suitable to trip a breaker or blow a fuse before an overloaded conductor fire occurs.
That said, the examples of grounding you displayed are surely adequate for those circuits.
The voltage is the same. It's the amperage that determines whether you need a 14 gauge or an o-4.
It's not the voltage that determines your wire size, it's the amperage and that's dependent upon what that circuit is powering.
A taser might have 50,000 volts but probably no more than a milliAMP,
otherwise people would be killed all the time being tased. Whatever the overcurrent protection is, you should always be using that wire size comparable to that overcurrent, for hots, neutrals and grounds.
Fusing current for 12awg copper approx. 235 amps. Not sure about melt almost instantly.
I have been trying to figure out why I am getting 120v from hot to metal box in my receptacles. There is no ground wire visible in the boxes nor is there any metal conduit in the house. I think after watching your video, it has to be grounded on the back of the boxes like you have shown in the video. I installed a GFCI receptacle on the first outlet anyway to be safe. Thank you for this video, I have not found any other explanation online.
@Sparky Channel so I have a house built in 1962 about to install a new Range Hood but the old one only have 2 wires & I just checked the conduit to the White wire & it wasn't even close to 120 VAC. So does that mean I can't use it?
You should do a video on the subject can romex be run in conduit I work in the electrical department at Lowe's and get this question a lot I always tell people that except in certain sleeving situations you can not run romex in conduit. This is how I was taught in trade school maybe you can shed some light on the subject thanks for the great videos
Good idea, thanks!
You CAN run Romex in conduit! You just need to protect the Romex sleeve wherever it exits the conduit, and the fill calculation changes. I think it's measured by the widest dimension of the Romex instead of individual conductor gauge. I've never had to worry about overfilling so never dug too deep. I have to pull a bunch of new wire in my remodel and it's just easier for me to pull Romex through the existing conduit where I can, then exit out of that with just Romex to wherever I'm going. This way I don't need a junction box in weird places, or to chew up my 2x4 framing with oversized holes for conduit. That said, if your conduit run stays in the same place there's no point in running Romex instead of thhn. Much easier to run the latter.
@@surfandsnowbord I think there is also a need to de-rate the Romex in conduit under some conditions due to possible heat build up at higher amperages. I am not sure when that comes into play, but I heard it mentioned on another reputable channel.
@@arlipscomb ... there was and probably still is a section in the code talking about derating for "double sheath" meaning your example of romex in a conduit but it's after a certain length. (drawing a blank here) There's also a section covering the use of conduit (or seal-tite) for protection where cable might be subject to damaged.
@@arlipscomb You're exactly right. Romex is not meant to be run through a raceway. That's Overkill. It's because of heat dissipation it would depend on how much of a load you have on that Romex but it's not necessary and it's not meant to be run through a conduit.
Thanks, makes sense...this is why in the older house wiring they used mostly metal BX wiring everywhere, which bonds each box in the house to the ground system...the old BX didn't even have a ground wire...in this example, the romex cable did not supply a good ground to the extended box...right ?
THANKS SPARKY YOU KEEPING ME WELL INFORMED
No problem, thanks!
ben watching for a long time., Thank you!
Thanks "ben". _Been_
Thank You Sir for this straight forward simple explanation. 👍
In my house the box is not grounded and there are no ground wire in the box. This is the way it is in 5 switch boxes in my house. I wish i could ground these.
In my house, the box is on a metal raceway and it is grounded through the raceway. My suburb only allows metal tubing not Romex etc even in 2020
It's my understanding the NEC does not count the conduit / MC as a ground. It's too easy for it to be discontinuous. The conduit can be grounded via an appropriately sized wire and bonding clamps. (as can the raceway "box")
@@jfbeam the NEC does allow conduit to be a ground as long as it is a complete system all connection are tight.
I have a question. So in my experience in my area, older homes in the 60's or more that do have metal boxes also have metal conduit that leads all the way back to the Main box. Does that situations provide a better ground? and if I have house ground attached to the main box do I effectively have a real ground?
I am not an electrician, but I believe the answer is yes that provides acceptable ground, with some caveats: if it's solid EMT then it's ok. But if it's the corrugated metal tubing then it probably would not pass code. The other thing is how the house is grounded. I think older homes only ground to the cold water intake and dont have grounding rods? I would check that too and make sure that the cold water ground is bonded to both sides of the meter (should see wire connecting from where it comes into the house, jumping over the meter and reconnecting to the other side).
Hopefully someone with more knowledge chimes in and corrects me if I'm wrong. I don't want to pass along misinformation. I have a house from the 50's with the same metal tubing/no ground as you are describing, this is what I've picked up the last few weeks from reading into how to ground without a total re-wire.
I have a house in the 1950s and I all the outlets are ungrounded. What should I do? I have been told I could install GFCI. Is this true? or im better to do swiss cheese with my drywall and replace everything?
I would like to know the same
@@gardnetbush9768 Take a look here, this guy covers the situation you have along with thousands of other people, on the old 2 wire/no ground problem. He references the NEC book also. Here: th-cam.com/video/lGTauC0hHlw/w-d-xo.html
Here: th-cam.com/video/lGTauC0hHlw/w-d-xo.html
You have three choices:
1. Leave it as is = free
2. Swap out the old breakers or receptacles with GFCI/ARCI protection = a few hundred bucks
3. Rewire the entire house and swap out the old breakers with GFCI/ARCI = very expensive
Option 2 will give you protection and be to NEC code but you still won't have a ground.
Option 3 will give you full protection with a ground and will be to NEC code.
@@jefflebowski918 Dude
I have a house that was built in 1955, it was ran with emt to the metal box. I would like to know will that provide protection or should I use a GFCI?
I’ve heard that EMT that old is problematic to provide a ground because of corrosion, loose, or missing connections.
Thanks. So if a metal light fixture grounding bar is attached to the metal box, then it is grounded?
Thank you Sparky!!!
I knew something was up when I was getting voltage on the box itself, turns out the switch box was never properly grounded !!
Wow, I'm glad that you discovered that.
OK that’s a good answer because there’s so many confusing answers and questions about this because I replaced a bunch of boxes on the porch direct sternal and I could not figure out and I was doubtful about connecting my ground to the box because obviously the box wasn’t ground at anything there was no conduit or anything it’s just going to a wood wall and I was pretty good with electricity on motors and heavy equipment so gave me some knowledge of this even though 120 is different butHave an old house from the 60s and all the grounds are tied together but there’s no grounding straps in any of the metal boxes so and I read that if you if you try to put one on there then you could create current and then it’s not good so I connected all mine just to the outlet to the ground wire and did not connect them to the box thanks for the info thanks for the clarity
What do you do if your boxes are like the one on the right, and not grounded?
Basically we're stuck needing to install GFCI outlets everywhere
@@rachelwatsky683 that doesnt solve the lack of grounding
@@IIlicit That was my concern, I read that installing a GFI protects you, yet will still test as not grounded. In addition your required to put a sticker on saying no equipment ground-----pretty confusing.
If you want it to be properly grounded, you will have to run t ground wire back to the electrical panel.
@@billybilly3333333333a gfci installed without a ground wire connected to it will not protect you any more than a 2 prong outlet with no ground.
So what do I do if my box is exactly the 2nd example? Old cinderblock house. Thx.
Plastic boxes are presently hard to find so I recently had to join three metal boxes to make a 3-gang box for receptacles. I assumed there would be a threaded hole in the metal box to attach a grounding screw. There wasn't. I installed spec grade Eaton receptacles. I hooked up ground connections to all three receptacles like I would have if they were installed in a plastic 3-gang box. I got the same reading whether I hooked the test lead to the neutral or to the actual ground or to the box. And why wouldn't I with 3 grounded receptacles being attached to the metal box?
Beware of of reading from the live wire and earth ground, if the earth ground is shorted on a neutral it will trsvel back on neutral line 1/2 the live wire curent.if live wire is 120 v ac the neutral will carry 60 v ac back to transformer if it is a alternating curent , direct curent has no neutral, it not travel back. Earth ground if wired correct has 0 v ac or dc. Earth. Ground is a dead short to ground.it cuts off breaker by a short not tempature. Regular panel breakers are tempature controled to cut off of mecury heat, you must reach that high tempature before it trips, most people catch on fire first.
hi my meter is only reading 86 volts not 120 , one prong on one of the hot wires the other prong on one of the 4 bolts in the box, all 4 bolts read 86 volts, is that enough grounding or no, by the way in my country both wires are hot containing 120 volts each
Same… did you ever get an answer to this??
@@jessm1638 same except 65v here
Hi, because of Covid 19 I got stuck in Vietnam and living in an old apartment, they don't have grounding, every electrical things with metal housing I touch I get an electric shock. The incoming wire that come into the apartment only have the 2 wire (live and neutral). How can I add a grounding wire to this apartment?. Can I use the neutral wire as grounding?
For old style house electric receptacle，the old style metal receptacle box is grounded，but only has two wire for hot and neutral coming out of box , do I have to pigtail the ground wire to replace outlet or the metal screw of the new outlet connecting to the metal box will do? The outlet tested shows good connection without the ground wire connected for the new outlet receptacle. Thanks !
I have the same thing and in my case the ground wires are connected to the outside of each box exactly like Bill showed starting at 4:00. They are 18 gauge and he said that they are not sufficient for today's code. I believe that they are considered "grandfathered in" so they're still okay until major renovations are made and electrical wiring would have to be upgraded. All the boxes show excellent ground when tested with a multimeter and all receptacles and GFCI receptacles work properly and show proper ground. The main panel has ground and neutral wires on the same bus which is normal for a main panel. You probably have the same situation. You could add a pigtail using an existing unused cable clamping screw or drill tap a new 10-32 thread if you have room, but IMO it's not worth doing that. You are still stuck with 18 gauge wire going back to the electrical panel. I changed all the receptacles to spec grade and they have a self grounding strap. This is compliant with NEC 250.146(B) the way I understand it, I am not an electrician, but I have experience with residential wiring. The self grounding strap and receptacle yoke must make contact with the metal box for this code to be valid, then a pigtail ground wire would not be necessary. You could get the same results from a residential grade receptacle without the self grounding strap, but it wouldn't comply with the code that I cited. The boxes are often recessed a bit, so a metal spacer(s) may be necessary to achieve the metal to metal contact. You can also coil some 14 gauge bare wire around the screw threads to achieve this. Make sure that you remove the paper screw keepers before hand.
Just discovered your channel and love your approach to educating viewers about home wiring. I also have a question regarding pigtails for grounding. I am wiring my garage for 20 amp service and have a box (plastic) with two outlets installed. 12 ga wire is a real pain to stuff into the box so I was wondering if you can use 14 ga pigtails for grounding the outlets. I keep getting mixed answers on this. Thanks for any help you can offer.
For a 20 amp medal box must be ground jumped , from earth ground bar , and yes on a 20 amp service circut , #14awg wire is correct size, the hot and neutral must be 12 awg withen 100 or less, if over 100 and less than 200 feet , the wire must be size 10 awg and earth ground size 12 awg.
Thanks for explaining how to properly test and show the answer! Now I could easily explain it to someone else too =)
Glad it was helpful!
Nicely Done ⚡️Great Job 👍 A Very Good Test Specially When I’m Dealing With A 1954 Motel Built Out Of Concrete Cement.Great Tips Thank You
Thanks Bigmo!
I need to do this test on the outlets in my 1982 condo unit because there is no ground wire. I didn't see a grounding screw in the metal box used for a wall switch and I bet the metal boxes for outlets are the same way.
Thank you. Very helpful.
Hi Sparky, I have old Knob & Tube wiring in my house. I was demoing a closet wall to make it bigger, there was a knob & tube wire running through the wall to an electrical outlet. I have to reroute the wire because it’s not long enough after I build the new wall. I was going to use 12 gauge romex wire and connect it to the knob & tube wiring in a junction box, so the wire will reach the outlet. I also thought, since I was putting a junction box in the ceiling of the closet, can I possibly put a lamp holder with a pull chain on to that junction box and get power by tapping into the knob and tube? Would I need to ground it because of the lamp holder, and how can I ground it? The wires are running in my crawl space and I don’t think there’s anything to ground it to. There just wood rafters and bricks and wood laths. I’d appreciate your help. Thanks.
use a plastic fixture for the closet, there is no ground connections on them so you don't have to worry about the ground wire, anything metal needs a ground, if you wanted to get a ground with out destroying everything look for a water pipe (metal) do a continuity test to a known ground just to make sure ground is there, clamp wire to pipe and bring into the junction box and now everything you run from that box will be grounded providing your using 2 wire with a ground....
This video was helpful. I have a situation where my house is older. It’s a concrete house and all the electrical work is pretty much permanent unless I wasn’t to bust concrete to run new electrical. 😂
Well the house is older and only has 2 wire electrical. I’ve replace all my outlets and when I test them with a tester, they all show to be wired correctly, except for one outlet that ready open ground. I tested to see if maybe it was a 240v but it’s 120v. I tested the wire and it appears one is hot and the other neutral. When I plug something it, it does work… but this open ground concerns me. Not sure why all the other outlets in the house appear fine except for this one alone. If I test it with the multimeter using the metal box as ground, I do get 120v circuit. Since it apparently is a good ground, would it be safe for me to run a ground pig tail to it? I’m concerned I may somehow energize the metal boxes and electrical plumbing in the house And if I someone touches it they might get shocked. Is this safe to do?
I have this same issue, did you ever figure it out? My theory is that in my case, the box does not lead to the service panel, but instead feeds off a light switch in that same room. The previous owners just drilled a hole in the wall to get a box in there but the wiring is outside and comes from the light switch, hence the box is ungrounded by all means.
Or u could ask if a grounded reciptical mounted to a metal j box give the metal j box grounding?
Is the metal box grounded if it only has the black and white wire but no ground wires or pigtail yet my GFCI tester shows correct connection(2 orange light).
The home electrical boxes are link through metal conduit straight to the breaker box and the wall are plaster walls.
Should I pigtail anything if tester shows as correct
In theory to be compliant (to present code )one would think that if the receptacle ( or switch) is not making direct contact to the metal j box that is designed to be used without a ground wire connected directly to the receptacle it's not considered grounded with out a ground pig tail to j box to receptacle. Ps I can't see any harm in (pig tailing grounds) redundant grounding a receptacle /switch; for the purpose of making a better positive grounding system. Good luck
In the second, unbonded box you showed, if 3 wire romex was used (romex with a hot, neutral and ground) and the grounding wire was attached to the ground screw of a light switch or outlet, would that count? I don't think so, but the metal of the receptacle would then be touching the box, as well as the ground wire. I think the box still needs to be grounded like you showed in the first box, but the local electricians here think it does not. Hard to get a straight answer on this issue.
I don't see the difference. They're all grounded.
I think what he’s trying to say to make it simple there’s so many answers to this that seem to be wrong but if the box is not grounded to the house or through conduit piping to the breaker box then you don’t ground the outlet receptacle to the box there’s no sense because it has no ground to go anywhere like the one man said it be like hanging a wire out a window it’s not gonna do anything ,Hope that helps
My house has a lot of old MC cable with no ground wires - the metal jacket is used as ground. I’m curious how good that is. In your example here: what if the second box were connected with MC to the first box?
Is it MC or AC? With AC the ground wire (if present) is only present in the cable and is used to bond the individual twists of the sheath together, this is cut off and only the hot and neutral are terminated in the box. This is per the manufacturers instructions and the NEC. Older AC cable (commonly referred to as BX) does not have this bonding wire, but the sheathing provides a ground fault path, just not up to modern standards. AC cable has some fire resistant paper around the wires that may be visible if you look where it enters the box, but it is usually removed when the wires are installed in a box.
There is a new contender, called MCap from Southwire which installs similar to AC where you don't need a ground wire to terminate in the box as it is listed and identified as having the sheathing in contact with the bonding wire is an effective ground fault path.
If your old wire has cloth covered rubber, you may want to look into having it replaced as the rubber is degrading.
I was switching out a ceiling fan fixture and discovered using a non contact tester the box is showing “hot” - is that because the hot wire supplying has been exposed?
That's the problem with some of those testers, they're too sensitive.
Would love to see a video of you exploring how 2023 NEC changes to 250.138 (A)-(C) affects how metal boxes can be bonded. i.e. pig tailing vs. wrapping an incoming EGC around a ground screw. I've seen both methods and there seems to be a lot of disagreement on what the code says.
Hey sparky!. I had a house that had recepticles where some were grounded and some were not. When I pulled them out, I noticed that the ground wire was cut short and stuffed in the back. My only choice was to bond the wire to the box to ground the recepticle. What do u think about that?.
in that case, it's safer to install a gfci receptacle
Yes, many of the old ground wires have been cut over the years by people who didn't know what they were. I would re-attach them and use GFCI until the old 2 wire system can be changed out in the future.
@@SparkyChannel
If you reattach the ground, would there be issues in using just a standard 3-prong outlet instead of a gfci? I just rented a home in a similar situation to the OP’s.
Measuring voltage alone with no load on the circuit can give you misleading info. You can have a 30 gauge wire (or a really bad connection) and have it show 120V with no load, but it has no real ability to carry current. As soon as you have a load the voltage drops like crazy. It's a bit dangerous to just measure voltage and call it a good connection.
Whats a 30 gauge wire.
@@thomasmarable6818 think like 1 strand of a stranded wire or a cat 5 cable wire. Very thin.
Good Content,GreatTips😀👍🏿
How about if the box is on block or brick
Same.
Thank You Sir 👍
Welcome 👍
Will the metal conduit provide a grounding?
It can, yes.
It can, but you still want to check them to make sure.
You're the best!
if I want to use a metal box grounded what is the maximum circuit breaker this box can handle? Thanks
Why would you want to use a metal box if you have a ground wire going from the box to the electrical panel?
@@FreeAmerican-mm2myI'm thinking they're saying they don't have a ground wire to the breaker box
Now I know how to test the box. Question though... Why was no grounding ok back then...and now all of a sudden it's important? In other words, is there some kind of data showing that homes in the 50's had lots of deaths or fires because of no grounding? Just wondering.
Aftrn ... back in those days it was ok to NOT have seatbelts in your car as well. The info is out there (usually insurance statistics) and the change in codes usually reflects a new problem found (or a better idiot found) and what they feel is the proper fix to solve the problem.
Back then there were fires, and deaths from ungrounded devices coming energized. As more, and more people started using electricity the number of deaths, and fires increased. At some point the code was changed because of this problem.
It's not "now all of a sudden it's important". Grounding, at least 3-prong receptacles, started to become the norm for new work in the 1960s. It was a natural progression of building a better product and what rupe53 and Melllvar said. Most people, even if they became aware of grounding's superiority, weren't going to go through the expense of replacing their house's wiring unless they perceived a danger. I think why we see so many TH-cam "how to's" currently about grounding is because there is so much old work still in use, it is aging badly and many new devices come with a 3-prong plug. I would never plug an expensive computer, etc. to an ungrounded outlet nor use an ungrounded GFCI for it. Some folks may want to get a HELOC and have all that old crap replaced.
so the box that isn't grounded has less voltage than the one that is. can someone explain to me how that works?
It's called "stray voltage" or "ghost voltage. There is a measureable amount of voltage in the wires, induced from the alternating current from the nearby power and neutral wires. It's not unlike radio signals. They are actually tiny amounts of electric current in the air. However, while those radio signals are measureable (your radio works) you could not power anything with it.
However, that stray or ghost voltage will dissipate instantly if it is connected to the slightest load. The presence of voltage is merely the difference between electromotive force in one place and another. Voltage alone does not indicate power. It also does not indicate the flow of electricity.
Thanks for the video =)
My pleasure!
I know a few people that would be happy to grab the hot wire with one hand and touch the metal box with tge other and report their findings to you!
LOL! Nobody do that, please.
@@SparkyChannel When I was a 1st. year apprentice I worked with an old timer who used to test that way. Between the callouses on his fingers and the full load of Irish Mist on board he hardly felt a tingle!
Haha... make sure the floor is wet!
@@thomasdragosr.841 LOL! Safety first!
Can you still going to make a video to fix a HOT/GROUND reversed receptacle.
Reverse the hot and ground...if need be I'll make a video but it's simple just read what the device is telling you. Or remember
Black the gold white to silver green to green
thank you sir!
very good information.
btw i was shocked by the outro, i thought u blew urself
So how to you correct it?
The safety ground conductor must be installed.
Bond the box to ground. (I'm surprised this even needs to be asked)
Emt provedes ground from outlet box to panel
I wonder if the (improperly) ungrounded junction box is finding electrical path through the wooden framing.
I don't know why the disconnected meter was showing voltage (I don't believe the given explanation).
There are a number of things that can induce a small voltage on an unconnected lead so it is not uncommon. For example, a very sensitive meter can often register voltage due to the leads inductively reacting with the wires of nearby circuit.
Capacitance. If you touch a live wire (while not grounded), you will become charged; there will be a small amount of current flowing in and out of you. If we go back to a water hose analog, water will flow to the end of the hose even if it's capped. (ignore the bubble of air)
@@arlipscomb Thanks Al
@@jfbeam Thanks jfbeam
Lou ... bingo... the moisture in the wood allows a small voltage leak.
Don't understand using a grounding pigtail and a self grounding clip at the same time
You don't have to. It's redundant.
Additionally, the metal junction boxes are specified because they are non-combustible compartments.
Always good information, and I like that you quote NEC directly when it's relevant . I have a question for you Bill, if I may? I have ungrounded outlets run with two wire NM cable (house is ~1980) in my basement. I have an outlet in the same room on a different breaker that is grounded. Is it ok/safe to connect a ground wire from the grounded outlet to the other outlets even though they are on different breakers, instead of running ground wire all the way back to the breaker box?
Some interesting things I've found related to this video while demoing the walls and discovering no ground, they are all metal boxes anchored to concrete foundation. When outlets are screwed into the box, my outlet tester shows they are grounded. I get 120V reading between hot and box and even to a nail in the concrete. The concrete wall surface even reads up to 100V. No continuity between the different boxes or box to neutral, so I'm guessing it is acting as a literal ground, but not enough to be a safe electrical ground for the outlets?
The breakers are only connected to hot,
they're not connected to a neutral or to the equipment ground. So it's irrelevant whether they're on the same breaker" as far as whether or not it's going to work for completing the ground to the equipment ground.
I heard that in older 50s and 60s homes just the fact that BX cables were used provided ground for the boxes. Can anyone confirm ?
It may if properly bonded to the ground. Just don't take for granted that the BX runs continuously and is properly attached to a grounded service box
@@danielrobert7181 Exactly. My house (built in 1961) has BX cables and so far, every box I've tested (including the two-prong ones) has shown a good ground, but I'm certainly going to test every one as I replace the outlets.
Thx, my question also.
How would you test for a plastic outlet box ? I have one outlet in the dining area which is showing no ground when I plug in my tester. Power is there but ground light on plug-in tester does not come on. It is a plastic box and the only one in the whole house not showing ground. Any advice ?
I am just a diyer. From what I understand however is plastic boxes have no ground attached to them like the old houses. The ground goes through the Romex wire and onto the outlet no pigtail attached to the box or anything like that. It needs fixed in two areas; not attached to the outlet correctly or ground wire is not connected to the breaker panel correctly. Hopefully you already figure out what to do.
Thank you sir.
Why would you even think is testing a plastic box. Plastic is an insulator. That makes is safe, just use the GFCI method of you want to change the socket.
So if a metal box has a ground to it and the black wire hits the Box your telling me it's not going to do anything?
_you're_
yes
You sound like Scotty a little .. please don’t take offense lol
No offense, thanks!
Honestly I thought that's who it was for the first few seconds 😂. Thanks for the video.
when measuring load to ground wire You really should have seen a slightly higher voltage then load to neutral wire.. because load to ground should have less resistance..
Thanks!
Outside of a calibration lab, your meter won't have enough digits to show the difference. (how much current does it take your meter to read a voltage? If it won't trip a GFCI, it's less than 4mA. Way less!)
@@jfbeam that makes no sense. Sorry...
@@fabulousfabrications1985 Any difference in voltage would be due to line loss. At at 1mA, the difference between 100ft of 12awg vs. 14awg would be about 0.0001V In most residential wiring, all three wires will be the same (12/2+G, 14/2+G) Don't take my word for it; measure the current draw of your own meters and do the math.
Is there a shortcut to bond the boxes in the house? Other than the OBVIOUS of following code; metal connections, ground screws/conductors...
Yes, you can use the self grounding clip found on some switches and receptacles.
Fluke is the best meter for electric but damn they expensive lol
I have a 1966 home with an outdoor junction box (metal) that is ungrounded. I called an electrician to ground the box for the install of a new light. All they did was attach a pigtail to the box….they said “the box will never be grounded, this is the best we can do.” …should I be concerned?
you mention an ungrounded box, how does the wiring get to the box? is just the cable? run through metal conduit? I have a similar situation but mine runs through a conduit all the way back to the Main breaker box so technically is grounded via the metal conduit where the wires are run through.
@@linkarmy09 the wiring gets to the box just via the cable, no conduit. I tested the box for ground and got ~40 V (vs the 120 V I should get if it were grounded).
Very concerned. I would be inclined to not pay that electrician.
Running a ground wire back to the electrical panel is the only true fix. It could be expensive.
Well, then, i'd like to see how to properly bond a metal box, lol 🤷♂️. I'll look up a video for that now, but if anyone can share that, i would greatly appreciate it.
Using Romex? As he shows here, the ground wire is bonded with the green screw.
T/Y for sharing this concept. It does appear that the center right knock out seal in the second box is installed incorrectly.
No
I try to not use metal boxes when ever possible. Plastic box is cheap.
But is a copper touching the inside of the box ?
If so then of course ur getting 120 …
Never depend on conduit system or boxes for grounding.
Why not?
Emt no but properly installed rigid conduit works great as a ground but for work done to code pull a ground
@@burnedupsparkytipsandrevie9597 correct
@@burnedupsparkytipsandrevie9597 it's like whend you bond to the water system if it's copper/galvanized.
@@burnedupsparkytipsandrevie9597 _works great as a ground_ no, it doesn't, which is why it isn't allowed by code.
👍
Thanks Josh!
No ground is isolated as a earth ground attached to neautral bar in a cheap made panel box , there are many, but useless on no fault, no fault is much expencive but a fact it saves lives. They must be a good panel, with a isolated earth ground seperate bar from neutral. or buy a south east asia panel box from philippines or veitnam or south korea, without a earth ground and make one seperate in the panel box and mound it on it , attached to the box also. Those must be seperate for a NO fAULT to trip at its fastest to save lives , plus for a isolated circuit as power grids require , all isolated computer call centers require, and all mega generators to level out and balance, so they will not shut down due to phases not balanced. This i know is a fact in experience building power grids in war zones. Building power grids for military bases and rebuilt citys usa military has destroyed in wars. Can not waiste time recranking the mega generators every 3 minutes. As bullets bouncing off your helmets and bullet proof vest , etc. Must get it correct first time. A second try can be fatal if alive. This is what kbr does with the usa military in war zones.
Can you have someone edit your comment so it is grammatically correct so we can understand your point?
@@PatHaskell i did not notice the spelling miss types. I corrected it, sorry my phone has tiny letters and i have big fingers, thanks.
Is the box the earth? No. There’s your answer lol
Thanks!
I think I could understand this better with a diagram to see what is going on.
I enjoy this stuff hahahaha
I have a blue point dmsc683a dmm
OK, thanks! Blue Point is excellent! Have a great day!
Here you are:
abload.de/img/sparkye7jkl.jpg
There was simply no ground provided to the second box. The squares are Wago connectors, the circle in the first box is the screw bonding the box to the ground.
🍻🍺
Cheers with beers! 👍
I like to guess on these videos before watching them. My guess was 'No'