"Floating" Neutral

[1793]

I have been seeing a great many sub-panel installations that I think are incorrect. I see the Neutral and EGC connected together in these sub-panels.

I would like some confirmation:

1. If a 50 amp 240V sub-panel, say 5 feet from main panel, connected with EMT, the neutral is to "float" while the EGC bar is connected to the panel. A seprate ECG is not needed since it is connected by the EMT.


2. If a 50 amp sub-panel, say 5 feet from main panel, connected with Romex, 4 wire, the neutral is to "float" while the EGC is connected to the panel.

I look forward to all replies.

 

[pierre]

1. Yes, 250.118(4)
2. Yes, 250.118(1)

 

[electricman2]

No connection between the grounded conductor and any EGC is permitted on the load side of the service disconnecting means. See 250. 24(A)(5)

 

[1793]

I have run out of body parts to count the number of violations of this sort. I thought I was correct, but seeing more wrong than right I was beginning to think I was making this up.

 

[bdarnell]

Sometimes I wish manufacturers would stop shipping green screws with the panels. Electricians see those and they just feel compelled to put the darn things in, no matter what the application.

It's an education issue I guess.

 

[don_resqcapt19]

Brad,

Sometimes I wish manufacturers would stop shipping green screws with the panels.

If the manufactuer does not provide a means to bond the grounded conductor to the enclosure, I don't think that he can get the panel listed as "suitable for use as service equipment".
Don

 

[bdarnell]

Of course, you're right Don. I was speaking mainly out of frustration. I too have seen more than my fair share of improper N-G bonds everywhere from the first panel all the way to the last device.

As for us, we try to educate our people as best we can and then call in the professional educators for the in-depth stuff.