solar with the 6 switch rule

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SunFish

NABCEP Certified
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ID
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Sr. PV Systems Design Engineer
Does a backfed breaker count as one of 6 max service disconnect switches when it is only a utility interactive grid tied inverter? (no batteries)
 

SunFish

NABCEP Certified
Location
ID
Occupation
Sr. PV Systems Design Engineer
I'm working on a job that has 6 main service breakers in a panel that is completely full. We can backfeed a sub-panel, plenty of room and meet all requirements of the 120% rule. Just not sure if the addition of the inverter breaker would count as a 7th service disconnect.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I'm working on a job that has 6 main service breakers in a panel that is completely full. We can backfeed a sub-panel, plenty of room and meet all requirements of the 120% rule. Just not sure if the addition of the inverter breaker would count as a 7th service disconnect.

That varies greatly by AHJ, so we cannot answer that for you.
In some places you can even add up to six PV AC disconnects if you can justify that many separate systems.
In other places you cannot add even one if you already have seven.
 

Smart $

Esteemed Member
Location
Ohio
That varies greatly by AHJ, so we cannot answer that for you.
In some places you can even add up to six PV AC disconnects if you can justify that many separate systems.
In other places you cannot add even one if you already have seven.
Six?
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I'm working on a job that has 6 main service breakers in a panel that is completely full. We can backfeed a sub-panel, plenty of room and meet all requirements of the 120% rule. Just not sure if the addition of the inverter breaker would count as a 7th service disconnect.

If you're backfeeding a subpanel with a load side connection, then no, that doesn't count as an additional service disconnect. If your AHJ tried to count it, that would be an interpretation I don't believe any of us have ever heard of.

The controversy is over whether it counts if it's connected directly to the utility supply like the other service breakers. If that's the case, then ask your AHJ.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
If you're backfeeding a subpanel with a load side connection, then no, that doesn't count as an additional service disconnect. If your AHJ tried to count it, that would be an interpretation I don't believe any of us have ever heard of.

The controversy is over whether it counts if it's connected directly to the utility supply like the other service breakers. If that's the case, then ask your AHJ.
He said "6 main service breakers in a panel that is completely full", which implies to me that the main panel is MLO. He could backfeed a breaker in a sub fed from a breaker in the main and it would be a load side connection; the only panel where the 120% rule would apply would be in the sub.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
He said "6 main service breakers in a panel that is completely full", which implies to me that the main panel is MLO. He could backfeed a breaker in a sub fed from a breaker in the main and it would be a load side connection; the only panel where the 120% rule would apply would be in the sub.

Isn't that what I said? :cool:
 

pv_n00b

Senior Member
Location
CA, USA
I'm working on a job that has 6 main service breakers in a panel that is completely full. We can backfeed a sub-panel, plenty of room and meet all requirements of the 120% rule. Just not sure if the addition of the inverter breaker would count as a 7th service disconnect.

A PV breaker in a load side sub-panel is not counted as a service disconnect.
 
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