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Upside Down Load Center

S

shazam

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Hi folks....another strange newbie question!

I have an existing main (200A) dis-connect on the outside wall of the house just under the meter. I also have in hand a new 200 amp main MEP with lugs for 200A pass-thru (see attached pdf). I'd like to use the new MEP to implement my solar. I know that the JHA will have the final say on this, but....

Is there anything in NEC that would prevent me from inverting the load center, running the 4/0 coming from the outside disconnect INTO the pass-thru lugs of this new MEP (sitting next to the S/A 15K), and running OUT (also 4/0) thru the new MEP main breaker into my S/A to get the 200 amp pass-thru the S/A offers? Thence from the S/A to the currently existing MEP of course...

It's a solid bus bar, so my assumption is that it would be safe, but code?...not a clue.

I would run my Chargeverter thru a breaker on the bus of the new MEP, to my battery bus. I will not have a sell-back agreement, and if I get any grief from the POCO on back-feed, I can (literally) flip them off, and still charge my batteries.

Thanks, and please be gentle with a newbie :)

Jim
 

Attachments

  • Load Center.pdf
    1.3 MB · Views: 30
Last edited:
Upside down load center is a common question for general electrical DIY.

I believe the usual issue for code compliance is around orientation of breakers. Main one is that ON is legally required to be up and OFF is legally required to be down. Generally this only affects the main breaker. But if you have, like, a single row landscape orientation load center (very unlikely just strawmanning and it actually does exist) then you can’t flip due to branch breakers going the wrong way.
 
Ive never ran into issue installing loadcenters "upside down" same codes still apply no more than 6'6" to highest breaker. You CANNOT however feed a passthrough panel from the lugs connected to the busbars. Your incoming power ABSOLUTELY must terminate at the main breaker.
 
I think that main breaker switches left/right, so inverting wouldn't violate the "up = on" rule (is that a rule?)

I see it is a 3R enclosure. You said existing main is outside. Where is this new box going to go???
Sounds to me like you do plan to put it inside, next to S/A which I suppose is also inside.

You could probably do this right side up as well, have to run the wires up from bottom in this case.

"Pass through lugs", are you able to do that and curve the cables as needed to go on to other load?

Supervstech said:
You want to connect a load to the lugs, wih no disconnecting means?
Click to expand...

Can disconnect out side at main. But if you unmount SolArk, you're left with cables ends to cap.
If you use Polaris at the new panel, can pull cables out of Polaris.

finite said:
You CANNOT however feed a passthrough panel from the lugs connected to the busbars. Your incoming power ABSOLUTELY must terminate at the main breaker.
Click to expand...

Why? Does code say that?

In this case he has no breaker at this sub-panel. The cables do terminate at the main breaker outside (that style of lug can't feed through.)
 
The documentation that comes with your load center will tell you what you can and cannot do.
Some are designed to be mounted in any orientation, yes horizontally included but some are not.
 
Sorry after your reply i had re read to make sure i wasnt misunderstanding something( i was) . Looking at that pdf, no you connat invert that load center it is a nema 3r so it as the rain cover and an opening for threaded hub, if it is not installed upright it is not rain tight, any penetration through the side(above the level of available breakers should a meyers hub for a raintight termination. The other issue you would run into without having a main breaker in the new MEP is you do not have the ability to instal an interlocking disconnect(its a device that doesnt allow 2 breakers to be energized at the same time.(used in generators often).

ETA, these are my personal experiences as an electrician in Connecticut, south florida and texas. Your AHJ will determine.
 
Hedges said:
Why? Does code say that?

In this case he has no breaker at this sub-panel. The cables do terminate at the main breaker outside (that style of lug can't feed through.)
Click to expand...
I think the difficulty here is that there was a bit of wall of text from the OP, and some people (esp me) probably just pattern matched the simplest question to answer and didn't bother to try to check if the whole thing made sense. For instance, I missed the part about this being outdoors, and I missed the part about a lot of involvement with the meter and where the service disconnect is.

I think I'm going to hold off on saying more (since my last potshot was useless) until a schematic and photos are provided. I'm not exactly sure why "can this be upside down" is the most important question out of all this, yet it's the subject of the thread. High suspicion of an XY problem.
 
Some of us put main breakers in sub panels, so we can have an interlock and select between grid/inverter feeding them. My main breaker (only) box by the meter gets "Service Disconnect" sticker, and the others get "Main" sticker.

I suspect OP is putting this panel and the inverter inside, but not sure:

"running the 4/0 coming from the outside disconnect INTO the pass-thru lugs of this new MEP (sitting next to the S/A 15K), and running OUT (also 4/0) thru the new MEP main breaker into my S/A"

Here is a situation where I would like a main breaker on this new panel. As described, its main lugs are fed from (200A?) main disconnect plus whatever S/A 15k can deliver (60A?). That exceeds 200A or 225A busbar.

Schematics help, would make the above obvious.

How about 200A service disconnect breaker at meter feeds input of S/A, and output of S/A feeds new panel?
I would also put interlocked breakers in new panel to select between S/A and grid input.

I would use Polaris to feed these such that I could shut off service disconnect, remove wires from Polaris to S/A, turn back on service disconnect.
 
Zanydroid hit in on the head. I probably threw everyone off with my title. My bad! I probably should have titled it, 'Can I run the current thru this box in the opposite direction from normal?'.

To answer questions posed above...the meter and the main disconnect are on the other/outside of this wall. That disconnect shuts down all POCO to the house.

THE S/A and this box would be in the basement, so no rain issues. Up/down is not an issue on the main breaker of the new box...operates left/right relative the 'top' of the box.

The over-riding question at issue is the new MEP breaker being used to shut down the power leaving this box, rather than the power entering it, which would be accomplished at the service dis-connect outside. The output feed from the S/A would go to the already existing MEP. Sorry about the confusion I introduced.

Jim
 
Last edited:
Please sketch a schematic.

I'm not clear if you are letting current from main disconnect plus current backfed from SolArk add together and go to main lug panel, or if you are connecting those two sources to opposite end of this panel.

I don't think either of those would be allowed, but if both fed it through a breaker (not lugs) then I think it could be OK.

You said "lugs", but now you say "new MEP breaker", adding to my confusion.

Oh, "Lugs for pass through", and .pdf shows breaker at one end, lugs at other. I think 120% rule would apply to backfeeding those lugs, 40A limit.

"the 200 amp pass-thru the S/A offers"

I would say no, can't feed 200A from grid to one end of this panel and have backfeed from SolArk at the other, exceeds 120% rule. I think SolArk can backfeed 60A from its inverter. More if AC coupled PV attached.

I would suggest Polaris tapping off the wire from service disconnect and main breaker feeding this panel, wires from it to SolArk. I would also consider an interlocked breaker backfeeding this panel, so it can be fed by SolArk or grid.

A schematic would be nice, so others following thread can see it with their actual eyes.
 
OK, I have a clearer picture. Sounds like you are wanting to use the 200A panel with MEP breaker as a cheap 200A disconnect switch?

(I'm going to have to think about whether there would be a better way to do this. At first glance I assume proper labeling may make this code compliant, but I'm not totally sure. There's a good chance there is a safety hazard from confusion and I don't know if labeling would fix that. The main breaker is special in that it is supposed to de-energize the busbar under normal operation)

Can you construct something from DIN mount 200A breakers (I don't know if these are available, just brainstorming)? Or buy a 200A fused disconnect switch (likely more expensive than a 200A panel with main breaker; maybe you can save some $ if it's not service equipment rated)

What is the ultimate goal? Provide a disconnect or bypass in front of the SolArk so you don't have to run all the way outside?

(Schematic would make this discussion a lot crisper, handdrawn is fine)
 
zanydroid said:
OK, I have a clearer picture. Sounds like you are wanting to use the 200A panel with MEP breaker as a cheap 200A disconnect switch?



What is the ultimate goal? Provide a disconnect or bypass in front of the SolArk so you don't have to run all the way outside?

(Schematic would make this discussion a lot crisper, handdrawn is fine)
Click to expand...


Well, you could do it with 100% rule (200% rule?). Sum of connections other than 200A main breaker do not exceed 200A. In this case only the feed-through taps, fed up to 200A. But then you could just buy a 200A main breaker only panel, like I did (no busbar), a bit under $200.

diysolarforum.com

200 amp double throw

I’m getting a Sol-Ark 15k and looking to install this double throw switch to switch from grid -off- solar. I’m confused as to how to wire it up. I think I should’ve bought the 3 pole to have an isolated N from researching on here. Can I still use this box? If so, how would I go about the wiring...
diysolarforum.com diysolarforum.com
 
Ugly but fast.....

POCO Power flow... meter > main disconnect > new MEP bus > new MEP breaker > SA grid in > SA load out > existing MEP > house
 

Attachments

  • ugly sketch.pdf
    384.6 KB · Views: 14
Last edited:
OK, feed through.
What is busbar rating, 200A? What is main disconnect breaker rating, 200A?
In that case 120% rule would say must protect backfeed to 40A.

Or, 100% rule (200% rule?) sum of backfeed and any other branch breakers not to exceed 200A.

How about a main breaker only box like in my photo, previous post link "200 amp double throw"?
 
Hedges said:
Well, you could do it with 100% rule (200% rule?). Sum of connections other than 200A main breaker do not exceed 200A. In this case only the feed-through taps, fed up to 200A. But then you could just buy a 200A main breaker only panel, like I did (no busbar), a bit under $200.

diysolarforum.com

200 amp double throw

I’m getting a Sol-Ark 15k and looking to install this double throw switch to switch from grid -off- solar. I’m confused as to how to wire it up. I think I should’ve bought the 3 pole to have an isolated N from researching on here. Can I still use this box? If so, how would I go about the wiring...
diysolarforum.com diysolarforum.com
Click to expand...
Yeah you can use 100% rule here.

There’s no loads so it’s basically just a switch

The panel will need 100% rule stickers on it, basically saying “no more breakers please”.

There may be extra inspection or plan check confusion caused by this even if legal
 
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