Grounded Neutral

[DAB41162]

I'm working on a system fed by a single phase 120/208VAC source. L1 and L2 are #2 from the plug to the main breaker. Ground is #6 and N is #10.

There are two power supplies and a PLC connected between L1 and N. There are no other line to neutral loads. The components are protected by 5A fuses. The circuit current is about 4A. #10 was used because it's the smallest wire the plug can handle.

The inspector says the neutral is grounded and needs to be #8 based on the NFPA 70-2023 Table 250.102(C)(1).

Yes, the neutral is bonded to ground inside the feeder panel. Are there are any other codes that would apply?

 

[infinity]

What is the "plug" that you've mentioned? And why is the neutral bonded?

 

[DAB41162]

The customer is wiring from their breaker to a female plug (rated at 120A) and connects to the male receptacle on the control panel. L1 and L2 are wired directly to the main breaker (80A). The neutral goes to a terminal block.

 

[LarryFine]

Normally, a neutral must not be smaller than the required EGC.

 

[retirede]

So only the N & G are connected through the plug and L1 is tapped off the #2 that is wired directly? If so, there’s a lot wrong here. Or maybe I’m not understanding it correctly.