EGC run inside the EMT conduit

[Ne0eN]

More Newbie questions:

My current design calls for a single 3/4" EMT conduit run from my attic junction box to the Inverter in the garage. I'm running 2 pairs of current carrying DC conductors (8 AWG THWN-2). Do I need 2 separate insulated EGC THWN-2 wires (12 AWG) per pair, or can I get away with a single insulated EGC conductor? Seems like 2 EGC conductors would be an overkill.

[emartin00]

You only need 1 per conduit run.

[Ne0eN]

Great! Thank you...

[inetdog]

1. Since you are running the wires inside a continuous run of EGC and have followed all bonding rules applicable to the use of EMT, the NEC does not require you to run an EGC at all.
2. However, if the installation also requires a Ground Electrode Conductor (GEC) you will have to run a wire for that purpose instead of relying on the EMT to serve that purpose.
3. If 12 AWG meets the EGC requirement for a single circuit and the GEC requirement, if any, then you only need to run one.

[Sunking]

Why do you need an EGC? No power is supplied to the panels.

Only thing required is an GEC and Bonding Jumpers which cannot run in conduit with load conductors. It is used to bond the panels to your AC Service Ground Electrode.

Sounds to me like you do not understand and have two different conductor functions mixed up.

[Ne0eN]

Why do you need an EGC? No power is supplied to the panels.

Only thing required is an GEC and Bonding Jumpers which cannot run in conduit with load conductors. It is used to bond the panels to your AC Service Ground Electrode.

Sounds to me like you do not understand and have two different conductor functions mixed up.

For my electrical drawings I used a company called SolarDesignTool.com. It generates design and permitting documents after entering all site specific details. In my case it came back with two (2) 12 AWG THWN-2 Cu EGC's (NEC 690.45a & Table 250.122) and four (4) 8 AWG THWN-2 Cu conductors for my DC Source Circuit between Junction Box and SolarEdge Inverter. All in 0.75" dia. EMT (NEC 300.17).

Also, SolarEdge Optimizers are part of the system...