Sub-panel & Main panel

[hardworker]

I was on a job with a 400amp main panel, that has a dozen sub-panels. I found one sub-panel, where the neutral bar and the grounding bar was connected together. I separated them as a sub-panel should be wired.

What potential problems are caused to the system by a sub-panel being mis-wired as described above?

 

[LarryFine]

See the responses to your other thread. Plus, that practice effectively places the two conductors in parallel, making the EGC a CCC.

 

[raider1]

When the neutral and equipment grounds are connected together down stream of the main bonding jumper they then become in parallel making the equipment grounding conductors carry neutral current.

This can cause any grounded equipment to now have the potential of arcing and causing a shock.

Chris

 

[Dennis Alwon]

See the responses to your other thread. Plus, that practice effectively places the two conductors in parallel, making the EGC a CCC.

That's what I was going to say. The OP's question is virtually the same as his other thread.

 

[hardworker]

I thought so, but I like understanding the science behind the trade.