Battery backup solar: Wiring the critical load panel
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- เผยแพร่เมื่อ 24 ส.ค. 2024
- There are always a lot of questions about the critical load panel. Hopefully this video will answer some of them.
Contact Johnny Valentine jvalentine@gainsolarservices.com
770-843-3497
Solar installation, design and Consuling. We can also put together kits and sell you the material for your solar project
OMG THANK YOU - I searched for a long time to find a video on how to wire my solar panels into my house. Your video was great I followed you instructions and the project is complete and my house is now running off of my solar system.
That’s great
Thank you!! I have been confused for how my solar was wired for so long and your video is the only one that really showed how mine was done! This helped me a ton.
Glad to help
Hello Johnny, As you know, I built my entire solar power system myself. I have always felt that the riskiest thing I did in that process was to rewire my panel. I have done exactly what you said, gone back and switched some things around to adjust things based on use that only I would know over time. Thanks!
It’s nice to understand your system. Most folks wait till the power goes out to try and understand their system
@@GainSolarPower I’m going through this sub panel plan right now in prep for an inverter in North Carolina (NEC2020). Few questions: 1) my main panel is recessed and would like to have the same for sub. Anything that is needed behind the panel for code compliance if recessed ? 2) I thought there is a 2” limitation on anything extending out from top/bottom of panel. Your trough seems to violate that. Maybe I misunderstood the code but want to verify because having the trough below both would solve so many problems. 3) I’m thinking having sub panel connected main panel via 100amp top breaker and an interlock breaker for inverter AC out. Any issues with that?
@@cgutowski471 it’s 6” not 2”. The panel is made to mount recessed
@@GainSolarPower Thanks but I though the 6” trough extending out in front of the panel is a code violation and can only be limited to 2”.
Hi Johnny, exactly what I needed to see and how to do it. Like you said, I know enough to be dangerous! LOL! My next project in a few months is adding on to my existing array so I have more panels and a battery back up. Sol-Ark 12k is what I'm looking at also. Glad the tax credit is still good for another a few more years. Keep up the great work with your videos. Let's get you to 10K subs this new year!
Hey man I would love to sell you that Solark 12 K and talk you thru the install
Sir, thanks so much for this. I have Tesla panels and am getting battery backup by Sunrun. I was trying to wrap my head around how this would work and thanks to your video I have a pretty good idea of what is going to happen.
Useful video. I am getting PV + battery installed - the inverter offers UPS option so I to add 2nd 'consumer unit' (as the fuse panels are called in UK). Perfectly doable for a sensible and smart DIYer, but not really legal - got to get a certified installer. At least I can educate myself and instruct them as to what I require. Thanks.
In a grid down situation I don't understand what is stopping the CLP from pushing power into the main load center - and then backfeeding to the grid?
I'm in the process of creating a critical loads panel. One thing I thought of that should also be done for all installs is to ensure that the power supplies from the Hybrid Inverter, when passing through grid power, is in phase with power supplies that "Could" come from the main panel to the critical loads panel. I'm sure there are different ways to bypass the Hybrid Inverter, if required, and that both wouldn't normally be lined up to do that, but, just in case, it could prevent a major fault. Error on the side of caution!
Thanks ben. There is a bypass and we keep track of thenphases
Wow. I ran romex to each load in the sub panel. Realized halfway through I didn't need the neutrals or grounds
Also the critical load sub panel now doubles as a main sub panel as if you turn off the main breaker in the main panel it will not turn off the circuit breakers in your critical load sub panel. Therefore are you now required to have a main breaker in the critical load sub panel?
I also assume that on the outside there may be a main grid disconnect (fused) near the meter and a solar pv ac disconnect (fused) next to it. I also assume that there is a supply /line side tap for overcurrent protection or a load side tap.
thats alot of assuming
Why have a separate ground? Seems like you can bond to the neutral bar and it goes to the same place, electrically speaking.
As a newbie my question is about the critical load panel. From your video I see that you physically took each of the circuit from the main panel and moved it into the critical sub-panel. You seem to have energize the sol-arc 12k from the main panel by a double pole breaker ( correct me where I am wrong). Which in turn will energize the critical sub panel. You then took the black wire running to each circuit breaker and extended them to the new location of the circuit breaker in the sub panel. The same is done for all other wires. Ok. Why choose this method over the more conventional method of leaving the circuits in the main panel and having a new circuit in the critical sub panel and running the wires from each circuit to the corresponding circuit in the main panel? I also assume that the panel box between the critical load panel the sol-arc 12k is a double pole double throw switch (manual transfer switch)
I’m confused. With both panels sharing the neutral can you have the main panel powered from the grid and the critical load panel powered by the inverter at the SAME time? That’s what I want to do. I’m assuming I’ll need a “generator” transfer switch setup or will have to move the neutral wires over too. I want to 100% run the critical load panel off Solar/battery with the inverter switching to grid if the load is too much or the battery level drops too low. I don’t have any MWBC.
Edit: just saw your reply about the insides of a Reliance 10 pole transfer switch - that’s what I was planning to use. Sounds like your setup is electronically the same as a Reliance transfer switch.
It be great if I could hear what your saying.
Hey Johnny, wouldn't you want to move both hot and neutral of each load over to the protected loads panel, and get rid of the wire bonding the 2 panels together? The way it is now, power will come in through the Sol-Ark, but return to the main panel (path of least resistance) causing inductive heating (minimally) in metal conduits.
Nope that’s more work and not necessary. You are asking a very common question but I do this professionally on almost every job. I would only do what you were talking about with an arc fault or ground fault circuit, the large white and green wires I show in the beginning of the video are totally bonding everything and creating a neutral return path
You want the neutral and and the ground of both panels bonded. You want the neutral and ground despártase of every subpanel after the main where the first and only neutral ground bond happens. But I have called engineers from multiple companies and talk to them about the sub panel wiring and they all have always said the neutrals from each circuit can remain in place.
@@GainSolarPower thanks for the clarification! I suppose once the grid goes down, it becomes a separately derived system which would need a neutral ground bond.
@@benssolarandbattery which it continues to use at the original neutral ground bond. There is another neutral ground bond in the transformer but there is no return current between the house neutral ground bond and the transformer neutral ground Bond
What about a situation where the breaker that feeds the inverter is flipped off while grid power is still available to the main panel? The inverter would be inverting battery power to the critical loads panel out-of-sync with the grid neutral. Does it matter what kind of inverter it is? I have a split-phase Aims Inverter with a UPS mode, and the manual is adamant that grid neutral and inverter neutral remain separate.
Last but not least to complete the set up I could add a standby generator which is wired to the sol-arc 12k with 2 wire start up and a battery charging circuit breaker in the critical load sub panel. Do you have any of these? If so the wiring could be complicated and I would like to know more about the wiring.
So as long as the inverter senses grid power it does not send solar/battery power to that critical load panel. Once grid goes down the inverter sends solar if available and or battery as neefed to power the critical loads? You are wago nut wire from the main service panel to the breaker moved into the crit panel.
Not quite how it works
@@GainSolarPower how does it ?
Great video! I learned a ton!
Great
If I am simply adding a new breaker entirely (freshly pulled circuit) can I just add in the breaker in the standard fashion to the critical load panel? I know the panels max current capacity is capable of supporting the new load.
Simply put, is there any interaction for a new circuit between the critical loads panel and main panel?
Thanks!
I just installed and had an electrician put in my critical loads panel. The inspector failed me because there wasn't a neutral for each breaker? He stated NEC code 200.4. We were using a bridge neutral from the sub-panel to the critical loads panel. We had to run a neutral to each breaker from my original sub-panel.
If you ever take a part one of those reliance 10 circuit transfer switches, they don’t have all the neutrals. You only have to move the hots. We’ve never had a problem with it. Was the critical load panels really far away from the main?
Still you can see from the way I built my systems addding neutrals wouldn’t be hard. Just time consuming. What part of the country are you in.
@@GainSolarPower The run from the sub to critical loads panel was more than 10 feet. We were able to have one neutral per breaker and use three hots to one breaker. It worked out, but, I figured out the electrical work is tough and reading the NEM would be like going back to school. A lot of information and it constantly changes year by year. Thanks for the reply!
Happy new year Johnny
Thank you for showing this. When you drill the 2x4 in the wall to take the 2 inch conduit between the two panels that doesn't leave much of the wall stud intact. I would be concerned about the strength of that wall stud. Maybe a metal plate with a 2 inch hole could be screwed to the side of the wall stud to get some strength back; What do you think ?
I think plumbers do far worse. Maybe a problem if its a load bearing wall? But they build houses out of studs so plumbers and electricians can make holes in them. That wall was actually a 2x6.
Yes I think plumbers do a lot more hole drilling. Nice to have 2x6 studs. No such luck here. What size hole did you have to drill between the two load centers ? Was it 2 inches ? I am thinking of adding a critical load panel myself. I don't have knockouts on the left hand side of the old ITE load centers so it looks like I will have to drill the steel as well as the wooden studs. I have two 200 amp panels to deal with here and then the additional critical load panel
Is the critical load panel the only thing that benefits from battery output during TOU shifting? Meaning, at night, when pulling from battery, will the inverter output only contribute to loads in the critical load panel? This is in the normal “grid-on” scenario. I know that only critical loads are energized from the battery in a “grid-off” scenario.
Yeah if it’s set up for TOU it will push offset as much as it can till battery is drained to setpoint
Johnny, am I correct in assuming that you only have need for a critical load panel when you are on-grid? Where I am totally off-grid, I also assume, I can turn off certain breakers if my PV system isn't producing enough power to keep my battery bank full of enough power to run my refrigerator, freezer or well pump. I obviously use my 7Kw diesel generator for backup but it is an option in a pinch. I couldn't quite hear the first part of this video due to the audio problem.
Yeah you do not need a critical load panel if you were off grid some people have system set up where the generator is the main and then the solar feeds everything else but they have a couple of large loads in the generator panel including the feed to the inverter charger
How would your neutral arrangement change, if at all, if you wanted to use a main breaker subpanel as critical loads panel, w/interlock kit, to allow inverter critical loads bypass (main breaker of sub fed from ~50A (for ex.) breaker in main, interlocked with inverter crit load input breaker)?
It would t change with an interlock
What switches the excess power to battery charging?
The hybrid inverter does this automatically. I’m using the Sol-Ark 12k hybrid inverter
@@GainSolarPower I want to power the heating element in a sand battery with direct DC power. Maybe best to just have dedicated solar panels for this load?
Thanks for the vid! Do you keep a breaker on the main panel, pigtail it to another breaker on the sub panel? Curious how you energize the breakers on the sub-panel if done another way. Love the Sol Ark!
There is a 60a breaker feeding thru to the solark and bypass that eventually makes its was over to the subpanel.
I have a LV6048 Inverter which I don't think has a common neutral. I want to move 10 Circuits from my main panel to the Critical Loads panel powered by the Inverter. Would I need to move the neutral and hots or can I use the process you have in this video?
Unless they are arc fault or ground fault breakers you should be fine running just the hots and neutral larger than the max possible combined amps of the circuits or the surge power of the inverter.
What purpose does that #6 neutral serve connecting the critical load panel and the main panel?
It’s keeps you from having to move the neutral of every circuit
Do you have any videos that show how to wire and bypass the inverter from the critical loads panel back to the main panel? I have an enphase system with sunlight backup and my installer is telling me there is no way to transfer the loads on the sub panel back to the main panel. I have a portable generator that I want to use at night or during overcast days and now my fridge and freezer are only wired to the sub panel. Thanks
Accomplishing this is pretty straight forward. Just saw this message.
Jv@gainsolarpower.com
Thanks for the video. Is the backup panel supposed to have the same circuits that the main panel has? In other words, should the backup system be an exact copy of the normal panel?
No man. It sounds like you better stay out of your electrical panel. The critical loads panels which you are calling them back up panel consists of the circuits you want to power during the outage.
Is this set up going to allow them to potentially sell power back to the grid? Or is that a different type of install. Sorry if that's a dumb question.
yes they can sell back but this is due to the type of inverter and if the power company allows sell back, doesnt really have much to do with this video
Always enjoy your videos. Very educational. Question. What is the name and model of the transfer switch. What transfer do you recommend for either the inverter feeding the critical load or generator
I use this switch
electrification.us.abb.com/products/switches-disconnects/spec-setter-emergency-power-transfer
Are you doing and install? Have you purchased a solark? We’d love to sell you one and talk you thru the install. Cheapest price on the internet!
@@GainSolarPower Yes I'd like to talk. Hire you for your consultation and planning
Im trying to find optimum spot to install my inverters, our main 200 amp service panel is in our laundry room, i was thinking i could mount the inverters on wall above the washer dryer but that wall has the water shut off valves about 3.5 ft up the wall snd i thought i bet code says any electrical type panel/inverter must be 3 ft away or on wall opposite of the water outlet/spigot/faucet. My main panel is 3 ft from that outlet. I could put the inverters in the bedroom closet which is behind that wall where washer dryer is with the water shut off valve. My other option thought is buy a 8x8 shed or 10x10 put about 30 ft to 50ft from the laundry room and main panel, which then also allows room for batteries. Only thing there is will need to insulate it and put a solar ductless to prevent getting too hot or too cold. But starting to thing this would be the best route. Any suggestions for us folks with no garage? Lol i am in NC north of charlotte. Any ideas greatly appreciated.
I like the shed idea personally. The inverters can’t go in a clothes closet.
@@GainSolarPower cool, thanks for the feedback, im guessing it would need be insulated, and probably have a solar high efficient ductless mini to keep from getting to hot or too cold.
im curious what amp breakers to inverter from main panel and from inverter critical load panel?
Double pole 60
Is it code violation to not move each neutral with associated circuit hot wire over to subpanel? I'm reading you can not just run one neutral from main panel to sub panel to cover all the hots that are now in the sub panel.
That’s a tough one. I’d leave it up to your AHJ/inspector. I’ve passed all my inspections doing it like the video shows. Moving the neutrals takes a lots longer. If the panels are far away I would move the neutrals with the hots but when they are close like that I bond the neutral bars with a big wire and that’s fine. I don’t feels that the code adequately addresses the scenario.
@@GainSolarPower thanks for the reply. I'm hoping to do the same as you did in video.
Well you have my blessing
Good video, thank you! Question, what if you're a "minimalist" and basically everything on your main panel is a "critical load"? How does this get wired with the inverter so it can still "transfer" to off grid?
I see how this CLP works and would benefit most, but in my case everything in my main is a critical load!
It would need to be wired in with a transfer switch the size of the service. grid on one side and solar on the other.
Make sense?
@@GainSolarPower may you expand on this answer. I have the same situation. The main breaker panel is my critical panel.
@@zedekmorenu7804 you can either run you whole house thru the inverter which has 60 amps pass thru and hope the inverter never fails or interrupt the conductors feeding the main panel with a 200a transfer switch and feed the grid thru one side and the solark thru the other and hook the main panel to the load side of the switch.
Hey Johnny, how exactly is the grid powering the critical loads panel? Are the panels joined in any way other than the neutral and ground connections?
In normal operation the grid passes thru the inverter but we also have a bypass in case inverter goes down that would connect the grid directly to the critical loads panel
Just make sure nutral and ground is sized correct
Roy what size for a 50 amp breaker
@@GainSolarPower I'd use 6 but with out looking 8 I think would work
@@royamberg9177 I once fixed a job where they ran the 6/3 Romex that fed the inverter from the grid out to a 3 pole fused utility required disconnect. They ran the neutral right through with the line conductors. For some reason the neutral fuse blew. It cause some electrical weirdness. Burnt up appliances. 82v at receptacles.
I don’t understand autotransformers but I think about them.
@@GainSolarPower never want the nutral to open it will cause all kinda hell to break loose
The neutrals are not used in the sub panel if you are just moving circuits, right? It's still required by code though? Thanks.
You need a neutral but I’ve never been turned down for not moving the neutrals. They are still working
@@GainSolarPower So you have to move both the neutrals and hot lines for 110v to the sub panel? Wouldn't it be easier to move the main power lines to a new main panel and leave the old panel alone with all circuits and connect the inverter to it? Is this possible within the code? Thanks.
@@markogrba1 sometimes is is easier to move the mains and a few of the bigger loads but o lot if you can put the new main panel in a place where you won’t have to splice the wires. If that makes sense
Question, Critical load panel....My whole house is Critical load panel....I run it off grid on a 12000 generator........what are you trying to say?
This is for a grid tie battery backup system.
Is that main panel still live while you are working on it?
Nh
Would you do this same thing for a Magnum 4448pae?
Yes
Does the Critical Loads Panel have to be recess mounted like the 200 amp panel is or can it be mounted directly to the drywall outer surface ?
I prefer surface mount but a lot of times they are recessed because they are installed during construction.
Surface mount is definitely easier to get into.
@@GainSolarPower Does it have to recessed by code. I think I prefer surface mount for the ease of wiring.
Don’t the ground and neutral also have to originate from the critical load panel? I know it still works this way, just thought code requires it. Thanks for the video.
Show me the code. Cant have two neutral ground bonds and the critical loads panel is a subpanel.
@@GainSolarPower All conductors of a multiwire branch circuit must originate from the same panelboard [210.4(A)].
You have a good point but the nec defines a multi wire branch circuit as
Branch Circuit, Multiwire. A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system
I’ve never had a single problem from just moving the hots, nor have I ever had an inspector call me out on it. I’ve even done a super neutral once.
Multiwire branch circuits are not common in residential anyway.
@@GainSolarPower maybe that’s where I’m not clear if I have a twin pole breaker run on 14/3 romex feeding hallway outlets on L1 and then lights on L2 then isn’t that a multiwire branch circuit? And I wired my critical loads panel the same as you just wondering if it will pass inspection.
@@Marker-er3ro yep that is a perfect example of a multi wire branch circuit.
Johnny what size sub panel should we buy for a Solark? Can you give a part number please. I have square D. Thanks you crack me up in your videos. How many personalities do you have? LOL
Get a square d panel main lug usually with as many spaces as you will ever need.
Where did you get those little yellow wire markers from ?
Mark that is just the Romex shield from the wire, more common is white.
Yeah it’s the jacket I stripped off the wire
need to kind of speak up and explain it better
Quick question… while ON grid… does the inverter limit the amount of amperage that can pass through it before it reaches the critical loads panel?
Example:
If the inverter/smart switch has a 40 amp breaker inside of it… does it only provide the critical loads panel a max of 40ps while On grid?
Thanks for your insight.🙏
Yeah you’d be limited to the max passthru amperage of the relays on the inverter. This is 60amp on a solark 12k. 200a on a 15k