705.12 POC

[George#9]

An installation is tapping after the meter before the main disconnect for a PV POC at a 277/480 main service. By definition is this a PV system disconnect or a service disconnect?, is a grounded conductor required (250.24C) from the tap to the disconnect in question.

 

[shortcircuit2]

If you don't install a grounded conductor...what will provide the groundfault path back to the source?

 

[GoldDigger]

I would say that you will need either a grounded conductor or an EGC.
I would apply the same rule to the PV disconnect as to the service disconnect, namely that if there is a grounded conductor it must be carried to the disconnect even if it is not used by the connected equipment.
Depending on the AHJ you either must or must not connect the grounded conductor to a GEC and bond it to the enclosure.
If the AHJ says you must bond it, it had better be there.

 

[Smart $]

An installation is tapping after the meter before the main disconnect for a PV POC at a 277/480 main service. By definition is this a PV system disconnect or a service disconnect?, is a grounded conductor required (250.24C) from the tap to the disconnect in question.

That's been debated without resolve. I'm on the PV System Disconnect side of that fence.

Even if it is "only" a PV System Disconnect, establishing an EGS for the PV system is required. That'll take running the grounded conductor to the disconnect and installing a grounded-to-grounding bonding jumper, or running a compliant bonding jumper from the service GES/EGS to the PV System. Essentially it amounts to the same thing either way... just variations in the requirements.

 

[jaggedben]

George, you're the inspector, it's up to you.

I tend to be in the service disconnect camp. But with that said, if the inverter does not require a neutral, then in my opinion it would be unfair to require both a neutral and an EGC. If in doubt, I suggest asking for a licensed electrical engineer to certify that the installation is safe.

I looked for a minute for the thread on this forum where we debated for [80]+ replies, but I couldn't find it right now.
EDIT: Here it is.

 

[ggunn]

That's been debated without resolve. I'm on the PV System Disconnect side of that fence.

Even if it is "only" a PV System Disconnect, establishing an EGS for the PV system is required. That'll take running the grounded conductor to the disconnect and installing a grounded-to-grounding bonding jumper, or running a compliant bonding jumper from the service GES/EGS to the PV System. Essentially it amounts to the same thing either way... just variations in the requirements.

In every jurisdiction we operate in in Texas save San Antonio, we do not bond ground to neutral in the disco. We simply run the ground from the PV system back to the grounding bar in the MDP the same as if it were a load side connection.