Meter base with two breakers

[PRERA]

For a supply side connection of a interactive PV system, a service in parallel with the exiting service disconnect is required. The interconnection requires tapping the service entrance between the existing main disconnect and the meter socket. On the case we are addressing the interconnection will be made at a 200A main lugs meter breaker assembly with two branch breakers. One of the breakers is feeding the Main House Panel and the other one is spare. The question is if connecting the Inverter Output circuit to a new backfeed breaker to be installed where the spare one is through the required PV AC disconnect is considered a supply side interconnection or if the two breaker assembly is considered the main AC panel and the interconnection a load side one. If the later, since there is no main, how is the PV system breaker sized?

 

[GoldDigger]

For a supply side connection of a interactive PV system, a service in parallel with the exiting service disconnect is required. The interconnection requires tapping the service entrance between the existing main disconnect and the meter socket. On the case we are addressing the interconnection will be made at a 200A main lugs meter breaker assembly with two branch breakers. One of the breakers is feeding the Main House Panel and the other one is spare. The question is if connecting the Inverter Output circuit to a new backfeed breaker to be installed where the spare one is through the required PV AC disconnect is considered a supply side interconnection or if the two breaker assembly is considered the main AC panel and the interconnection a load side one. If the later, since there is no main, how is the PV system breaker sized?

If you are upstream of the service disconnect, you are supply side, although there will be a PV disconnect in the circuit instead.
When you have multiple handles in the service disconnect, one of which is only PV backfeed, I would be inclined to say that some AHJs will call that a supply side connection and others will try to call it a load side connection.
My personal inclination is that the wording of the Code section makes your hypothetical two breaker situation supply side.

 

[jaggedben]

The PV breaker is sized at 125% of the maximum inverter output regardless of the type of connection.

I agree with Golddigger on the rest. Some AHJs will try to apply the 120% rule to your panel but in my experience they come around when you point out that there is no utility breaker feeding the busbar.

 

[Zee]

The PV breaker is sized at 125% of the maximum inverter output regardless of the type of connection.

I agree with Golddigger on the rest. Some AHJs will try to apply the 120% rule to your panel but in my experience they come around when you point out that there is no utility breaker feeding the busbar.

Just to be 100% sure: If what you have is a "split service panel" then i agree with above posters.
(Ie a panel with space for two breakers, and each breaker is a service disonnect / "main disconnect". One breaker does NOT feed the other breaker.)

Putting a new PV breaker in there counts as supply side.
Hence, you can install a PV breaker up to the rating of the panel, and must size it to be no more than 125% of the inv. output amps.


Also this PV breaker may count as your ac disconnect that you refer to. You may not need a separate ac disco.....check with utility.
As long as inv. is line of sight from PV breaker in MSP, it meets CODE.
Check w/ utility, though......

 

[jaggedben]

...
Also this PV breaker may count as your ac disconnect that you refer to. You may not need a separate ac disco.....check with utility.
As long as inv. is line of sight from PV breaker in MSP, it meets CODE.
Check w/ utility, though......

It depends on the AHJ. The code requires DC and AC discos for an inverter to be 'grouped'. One AHJ I work in says that grouped means within 6ft and line of sight. Another AHJ wants a separate AC disco even if it's connected to the breaker enclosure with a nipple. Some other AHJs don't enforce any policy on 'grouped' consistently, or don't enforce the requirement at all.

 

[Carultch]

Just to be 100% sure: If what you have is a "split service panel" then i agree with above posters.
(Ie a panel with space for two breakers, and each breaker is a service disonnect / "main disconnect". One breaker does NOT feed the other breaker.)

Putting a new PV breaker in there counts as supply side.
Hence, you can install a PV breaker up to the rating of the panel, and must size it to be no more than 125% of the inv. output amps.


Also this PV breaker may count as your ac disconnect that you refer to. You may not need a separate ac disco.....check with utility.
As long as inv. is line of sight from PV breaker in MSP, it meets CODE.
Check w/ utility, though......

Utilities usually require a visible open disconnecting means. Few if any breakers are visible open.