Electrical panel upgrade

[sensij]

Sadly, I won't be able to wait that long, so I'll have to go an alternate route.

What is the rush? CA's next code cycle should roll in next year, so there would still be time to get in before the federal tax credit expires.

[CraziFuzzy]

What is the rush? CA's next code cycle should roll in next year, so there would still be time to get in before the federal tax credit expires.

CA didn't adopt the 2011 NEC until 1/1/2014.

[sensij]

CA didn't adopt the 2011 NEC until 1/1/2014.

Ah, yeah. Sorry. Is the tax credit your only concern? It might still be worth hanging tight until it becomes clearer if it will be extended into 2017 or allowed to expire.

[CraziFuzzy]

Ah, yeah. Sorry. Is the tax credit your only concern? It might still be worth hanging tight until it becomes clearer if it will be extended into 2017 or allowed to expire.

No, the tax credit is not a primary concern for timing, just the earlier I get the system online, the sooner it's paying for itself. Plus, it will be a patio cover as well, which the forewoman has been clamoring for for years.

[awhite]

Service panel bus bar rating

I can't tell what the bus bar rating is because the factory sticker from the inside panel cover of the service panel is missing.

The service panel does have two 2-pole MP-T breakers, a 40 amp to the A/C and a 100 amp to an inside sub panel.

The electrician I contacted says there's no way to find out the busbar rating even by removing the deadfront without the manufacturer sticker.

Advise on how to determine service panel OCPD and busbar rating without the manufacturer sticker?

I need to find out if a service panel upgrade will be needed for a Solaredge 5000 inverter.

Thanks in advance.

[SoCalsolar]

Best way in your situation is

If the homes on your street were built by the same builder you can check neighbors panels until you find some paper. Other than that I believe your electrician is right.

[foo1bar]

I can't tell what the bus bar rating is because the factory sticker from the inside panel cover of the service panel is missing.

The service panel does have two 2-pole MP-T breakers, a 40 amp to the A/C and a 100 amp to an inside sub panel.

The electrician I contacted says there's no way to find out the busbar rating even by removing the deadfront without the manufacturer sticker.

Advise on how to determine service panel OCPD and busbar rating without the manufacturer sticker?

I need to find out if a service panel upgrade will be needed for a Solaredge 5000 inverter.

Thanks in advance.

Look for anything that tells you what model you have.
And get the information from the manufacturer about that model.

If your neighbors have the same panel (ex. same development, built at the same time) get the info off sticker on their panel.

And don't be too shocked if you have a panel with a 125A busbar that somebody has overloaded by putting 140A of breakers into it, rather than replacing it.

[CraziFuzzy]

And don't be too shocked if you have a panel with a 125A busbar that somebody has overloaded by putting 140A of breakers into it, rather than replacing it.

Putting 140A of breakers on a 125A panel is not overloading anything.

[SunEagle]

Putting 140A of breakers on a 125A panel is not overloading anything.

.....

Misunderstood the above post and put down the wrong info.

[sensij]

It is more like under protecting the busbar.

The load breakers are not intended to protect the busbar. That is the job of the supply breakers. In most situations, there is nothing wrong with 140 A of load breakers on a 125 A panel.

[SunEagle]

The load breakers are not intended to protect the busbar. That is the job of the supply breakers. In most situations, there is nothing wrong with 140 A of load breakers on a 125 A panel.

My bad. I thought that "140A" was referring to the single Main or the "supply" breaker and not the total amperage of load breakers.

Thanks for catching my comment. I do appreciate someone making sure others do not get the wrong impression about the job of over-current devices.

[CraziFuzzy]

The load breakers are not intended to protect the busbar. That is the job of the supply breakers. In most situations, there is nothing wrong with 140 A of load breakers on a 125 A panel.

That is correct - in fact, my current "100A" panel has a 100A/100A feeder with 190A/205A of load breakers on it, and this is entirely okay. The job of the load breakers is to protect the wire downstream of them. The job of the supply breaker(s) is to protect the buswork between them and the load breakers (and to some extent, protect the line TO the panel from the pole/xfrmr/etc).

[foo1bar]

The load breakers are not intended to protect the busbar. That is the job of the supply breakers. In most situations, there is nothing wrong with 140 A of load breakers on a 125 A panel.

From the description, I believe that the 100A and 40A breakers are the main breakers - that they're the first breakers after the meter. Together they would be protecting the busbar, the wire from the utility to the meter, etc. And they'd be individually protecting the lines from them to the subpanels.

And that means that if there's 40A going through the A/C, and 100A going through the house there's 140A going through that bus bar.
Maybe there's some rule in the codebook that gives you some leeway because you're unlikely to use both to full capacity at the same time.
And it's probable that the 125A busbar is able to handle 140A (that's only ~10% over it's stated capacity - most likely it's engineered so that wouldn't cause a fire)
But unless someone can show me how that'd be up-to-code, I believe that 140A of breakers as the limiting factor on a 125A busbar is overloading that busbar.

[sensij]

This was the comment that started this tangent.

Look for anything that tells you what model you have.
And get the information from the manufacturer about that model.

If your neighbors have the same panel (ex. same development, built at the same time) get the info off sticker on their panel.

And don't be too shocked if you have a panel with a 125A busbar that somebody has overloaded by putting 140A of breakers into it, rather than replacing it.

From the description, I believe that the 100A and 40A breakers are the main breakers - that they're the first breakers after the meter. Together they would be protecting the busbar, the wire from the utility to the meter, etc. And they'd be individually protecting the lines from them to the subpanels.

I guess since the original comment came from foo1bar, and he seems to have intended the 140 A to be describing supply breakers, I've misunderstood. However, in that case, I would object to the suggestion that 140 A of supply on a neighbor's 125 A panel should not be surprising. Since a permit and inspection are required in most locations to benefit from net metering or to add new service, and attempting to DIY a second service breaker is stupid, I would doubt many people would get away with overloading the bus. That is just too easy for the AHJ to catch.

[CraziFuzzy]

I honestly hadn't seen awhite's post, which is what I think foo1bar was responding to. awhite was describing his current main disconnect panel, but he only listed the 2-pole breakers that were in the panel, in this case, his 100A breaker to the suboanel inside, and a 40A load breaker for his air conditioner.

I can't tell what the bus bar rating is because the factory sticker from the inside panel cover of the service panel is missing.

The service panel does have two 2-pole MP-T breakers, a 40 amp to the A/C and a 100 amp to an inside sub panel.

The electrician I contacted says there's no way to find out the busbar rating even by removing the deadfront without the manufacturer sticker.

Advise on how to determine service panel OCPD and busbar rating without the manufacturer sticker?

I need to find out if a service panel upgrade will be needed for a Solaredge 5000 inverter.

Thanks in advance.

Unfortunately, you cannot use load breakers (which these are) as any indication on what the panel's buswork is rated for.