AC Disconnect - Groung or bond to neutral?

[bryankloos]

Hey Guys,

I have about a 70' homerun of 3 x #3 THWN-2 and #6 GEC which goes to the AC disconnect and then another 8' to a line side connection in the MSP.

Do I need to run the GEC into the AC disconnect, break and attach to a ground lug in the AC disconnect?
The other option is to bond the box to neutral with the bonding screw and run the #6 GEC straight to the MSP.

My concern is keeping the box from becoming an electrocution hazard in the case of a short..

Thoughts?

[bryankloos]

One other question...

Does it matter which side of the AC disconnect is line and load, and if so, which is line, the PV array or the mains?

I'm assuming the mains should bond to the fuse side, then switch, then leads to the PV array, so that the switch is fused...

Thoughts?

BK

[inetdog]

The wire in a feeder which is grounded but does not normally carry current is an EGC, not a GEC.
In your case the fact that you have a line side connection makes it less clear between your main panel and the PV disconnect.
Perhaps 50% of AHJs require an EGC and no bond at the disconnect while the rest require a bonding jumper (not exactly a GEC) and a bond at the disconnect.
You need to check with your own inspector or AHJ.

In the long homerun it is definitely an EGC and it must not be bonded to neutral at the inverter end.

[bryankloos]

OK, sorry about the misclassification regarding the EGC and GEC.

My system consists of LG310s, S280 microinverters, soladeck AC pass through, dedicated PV panel in attic, homerun to AC disco and then to MSP.

Can you please confirm I have this correct in my mind?

Enphase trunk cable and racking grounds connect in a soladeck box at ground lug. L1, L2 N and EGC continue to the PV sub panel with NO neutral to ground bond screw. L1, L2, N and EGC travel the home run to the AC disco where L1, L2 and N land on the switch contacts with the GEC passing through but making no contact at a ground lug. Then L1, L2 N and GEC go the MSP.

Depending on what the AHJ wants, I can land the GEC on the ground lug in the AC disco or I can use the bond screw to ground the enclosure.

Am I missing anything?

[inetdog]

That's pretty much it.

Under some circumstances the NEC allows one wire to serve as both EGC and GEC, and that usually happens with Enphase. Make sure it is large enough for each of the requirements.

A licensed electrician should be able to sort it out for you.