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More residential PV questions

TimNY

TimNY

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Joined
Jan 13, 2010
Messages
1,133
Location
Charleston, SC
Scenario:

6x6x4 PVC junction box screwed to roof.

Conductors from inverter (DC array) are routed through the wall of the house and enter through the bottom of the box.

Short length of carflex run from connector in side of box to underside of PV array.

USE-2 conductors run inside carflex to array.

6ga bare EGC run outside of carflex to array.

Questions:

If I were to open this JB, should I be seeing metallic conduit entering the bottom of the box? [690.31(E)]

EGC is permitted to be run outside the carflex per 250.134(B) ex.2, but is it acceptable to drill a hole in the JB, run the EGC in there and seal with silicone? Or must it enter through a connector?

Would the other end of the carflex (largely protected from the weather by being under the array) need to be sealed?

Do you require a cable gland at the end of conduit where the conductors emerge, or do you accept sealant (ductseal, silicone)?

I am not responsible for electrical inspection.. but I was on a roof today.
 
What is the source voltage of the PV system?

There are quite a few PV system changes in the 2008 NEC, is that what your questions are based on?

Where will the conduit drain?
 
Yes, we are on 2008 NEC. I only have 2005 since I don't do electric, so I am looking at that for the section numbers. I will have to look at the voltage tomorrow.

Conduit will drain into the PVC box, which most likely will drain down the conduit inside the wall and into the inverter.. Thus the question.. This supposedly already passed. I was checking the bolting of the panels to the roof.
 
Just looked through the file and I have no electric specifications for this particular install. This project is a year old; we implemented the "Simplified PV Permitting Process" within the past year, so I do have specs for newer installs.

Just grabbing from a new install by same contractor, for a hypothetical situation:

Panels: VMP: 30v PMAX: 235w Max Voltage: 600V

Inverter: Max DC Volt Rating: 600v, Nominal AC Voltage: 211-264v, Max AC Current 25A, Max OCPD Rating: 20A

Strings of 8 panels.
 
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