Grouping of AC main PV disco

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hhsting said:
So I have had contractor tell me that PV AC main fused disconnect connected supply side of the main service disconnect is safer outside exterior wall of dwelling unit then inside grouped with main service disco.

This is because if their is fault the fused disconnect gets very hot and melted the exterior plastic sidings dwelling unit. If the PV AC fused disconnect is inside dwelling unit grouped next to main service disconnect in basement on open stud the damage would be much worse.

What do you all think?
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Two points:

First, any argument made about the PV disconnect applies to the service disconnects and vice versa.

Second: Between rapid shutdown and the new emergency disconnect rule in 230, the code is basically requiring outside disconnects for everything these days, for quicker firefighter access. While I'm skeptical that firefighters' needs suddenly changed in the last decade, that's a hundred times more logical than the reason they gave you. They're just making something up to justify the way they want to do it.
 
hhsting said:
So I have had contractor tell me that PV AC main fused disconnect connected supply side of the main service disconnect is safer outside exterior wall of dwelling unit then inside grouped with main service disco.

This is because if their is fault the fused disconnect gets very hot and melted the exterior plastic sidings dwelling unit. If the PV AC fused disconnect is inside dwelling unit grouped next to main service disconnect in basement on open stud the damage would be much worse.

What do you all think?
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The AHJs I deal with require a PV AC disconnect on an exterior wall. If it is a supply side interconnection to an interior MDP, sometimes we have to install a second disconnecting means with OCP inside.
 
ggunn said:
The AHJs I deal with require a PV AC disconnect on an exterior wall. If it is a supply side interconnection to an interior MDP, sometimes we have to install a second disconnecting means with OCP inside.
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Sometimes? What would those sometimes be and why?
 
hhsting said:
Ok but why require it to be on exterior wall and not grouped with service disco interior? How do first responders know if service and PV disco are not grouped?
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Code requires a directory placard to be installed at the service disco and the PV disco if they are not grouped. For commercial systems we are frequently required to make placards even if the discos are grouped.

The disco on the outside wall and the one inside when it is required perform different functions. The one outside is there so the utility can turn off the PV system whenever they want for whatever reason they have.
 
ggunn said:
Code requires a directory placard to be installed at the service disco and the PV disco if they are not grouped. For commercial systems we are frequently required to make placards even if the discos are grouped.

The disco on the outside wall and the one inside when it is required perform different functions. The one outside is there so the utility can turn off the PV system whenever they want for whatever reason they have.
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Which code reference requires placard when PV AC is not grouped with service disco?
 
hhsting said:
Hmmm even in dwelling units PV AC disco is require outside? Imagine placard outside showing all sources of power
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An exterior PV AC disco is an AHJ requirement most places, and when the main service disconnect is inside or anywhere else other than grouped with the PV AC disco, then yes, placards are needed at both discos even for residential PV systems. Sometimes when we encounter an interior MSD the local codes have changed since it was installed and we have to install a new one outside under "you touch it you fix it".
 
The rapid shutdown disconnect is required to be exterior. Otherwise there is no code requirement for an outside disconnect, and most AHJs in my experience (unlike ggunn's) don't otherwise require one. That is, if the main supply side disco were inside and something else was outside that initiated rapid shutdown that would be fine.
 
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