can we connect battery and load down stream of Siemens solar ready breaker with parallel energy inut

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Designer101

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Solar and ESS Designer
Hi all My understanding is that if we connect inverter to Simens soalr ready Panel (MC3042S1400FC) with parallel source input, its same as supply side connection. NEC 2020 and need to follow 230.82(6) and 250.25??
Also If this is Supply side connection then can we connect Loads downs stream if we keep battery and add Tesla gateway.
attatched is the SLD.
 

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Designer101 said:
Hi all My understanding is that if we connect inverter to Simens soalr ready Panel (MC3042S1400FC) with parallel source input, its same as supply side connection. NEC 2020 and need to follow 230.82(6) and 250.25??
Also If this is Supply side connection then can we connect Loads downs stream if we keep battery and add Tesla gateway.
attatched is the SLD.
Click to expand...

I don’t think there’s an issue with disconnecting means, 6 or less is all that’s required.

I’ve installed that exact panel a number of times. I guess I just don’t see why you’d want to. In theory your load on the existing sub panel would be what you’d want to protect?
 
In my opinion if you put loads on the 'parallel energy' breaker it simply becomes an additional service disconnect. The code allows the sum of multiple service disconnects to exceed the rating of the service as long as the calculated load does not. See 230.90 Exception 3.

I suppose an AHJ could call out 110.3(B) that putting loads on the parallel energy breaker violates the instructions. But this seems argumentative and I haven't had any do that to me.
 
jaggedben said:
In my opinion if you put loads on the 'parallel energy' breaker it simply becomes an additional service disconnect. The code allows the sum of multiple service disconnects to exceed the rating of the service as long as the calculated load does not. See 230.90 Exception 3.

I suppose an AHJ could call out 110.3(B) that putting loads on the parallel energy breaker violates the instructions. But this seems argumentative and I haven't had any do that to me.
Click to expand...

The only other thought is that the breaker slot on the parallel disconnect isn’t visible when you open the disconnect and load center on the right (see photo). You have to remove an additional cover that is not hinged.
1e09eb01c0ea0ddfbed96b50aeb8aa9a.jpg
 
BackCountry said:
That’s true, but I wonder how that will work with 230.71 under the new code.
Click to expand...

With this particular panel the 'parallel energy' breaker is in it's own compartment so that's moot. Also it's still a side issue.

For what it's worth I've yet to hear of any AHJs disallowing 400A panels with two main breakers due to the new 230.71. But it's only been a few months and I haven't been installing them myself.

Perhaps under the 2020 code there is still a tiny bit of room to argue that the 'parallel energy disconnect' is not a 'service disconnect' and therefore not subject to 230.71, but that is an increasingly untenable position given various changes over the last couple cycles. (And it was always legalistic, not safety or physics minded.)
 
jaggedben said:
With this particular panel the 'parallel energy' breaker is in it's own compartment so that's moot. Also it's still a side issue.

For what it's worth I've yet to hear of any AHJs disallowing 400A panels with two main breakers due to the new 230.71. But it's only been a few months and I haven't been installing them myself.

Perhaps under the 2020 code there is still a tiny bit of room to argue that the 'parallel energy disconnect' is not a 'service disconnect' and therefore not subject to 230.71, but is an increasingly untenable position given various changes over the last couple cycles. (And it was always legalistic, not safety or physics minded.)
Click to expand...

I think it would be nitpicky for sure. I’ve installed that particular panel a number of times, my only concern is to the layperson trying to open all of the service disconnects in an emergency — the left section is somewhat non-obvious compared to the right.

That being said, I love that panel because it solves a lot of problems for us on single phase large ground mounts where we have a 120 or 160a backfeed.
 
BackCountry said:
I don’t think there’s an issue with disconnecting means, 6 or less is all that’s required.

I’ve installed that exact panel a number of times. I guess I just don’t see why you’d want to. In theory your load on the existing sub panel would be what you’d want to protect?
Click to expand...

jaggedben said:
In my opinion if you put loads on the 'parallel energy' breaker it simply becomes an additional service disconnect. The code allows the sum of multiple service disconnects to exceed the rating of the service as long as the calculated load does not. See 230.90 Exception 3.

I suppose an AHJ could call out 110.3(B) that putting loads on the parallel energy breaker violates the instructions. But this seems argumentative and I haven't had any do that to me.
Click to expand...
i actually asked Tesla design review beore posting here.
this was their resposne:
"
It is not acceptable to land the Gateway feeder in the supply side slot of a PV-ready panel.  NEC 230.82 details acceptable equipment which can be connected to the supply side of a utility service disconnect. Interconnected electric power production sources (which Powerwall & Solar are considered) are acceptable to connect to the supply side of the service. However, there are always backup loads downstream of the Tesla Backup Gateway, and loads are not acceptable equipment to tie off on the supply side of the service. As a result, we cannot interconnect the Tesla Powerwall System to a supply side only breaker slot. 
"
 
Yeah they're reasoning is just wrong.

If you leave aside Siemens labeling, it's just another service disconnect. And 230.90 exception 3 says that the only thing that ultimately matters is the calculated load. So 230.82 just doesn't come into it. It would just be a service with 3 main breakers.

So the only thing that matters is whether the Siemens labeling prohibits you from using it for loads, which would be a really strict reading of 110.3(B). There's really no other code section at issue.
 
jaggedben said:
Yeah they're reasoning is just wrong.

If you leave aside Siemens labeling, it's just another service disconnect. And 230.90 exception 3 says that the only thing that ultimately matters is the calculated load. So 230.82 just doesn't come into it. It would just be a service with 3 main breakers.

So the only thing that matters is whether the Siemens labeling prohibits you from using it for loads, which would be a really strict reading of 110.3(B). There's really no other code section at issue.
Click to expand...
yes thats what exactly what simens meant to say may be when i contatced their technical support.

"This installation would not be permitted. The solar backfeed provision is listed as a backfeed slot ONLY, you cannot put any load devices off of that solar backfeed provision.
Siemens Industry, Inc.
Customer Services
Technical Support
Customer Care Center: 800 333 7421
Outside USA +1 423 262 5710
 
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