No Ground in Sub-panel

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bbhatt

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Hello,

We had to install a sub-panel for a restaurant rennovation,
work included adding some ten 20A outlets for additional equipment

An electrician did all the work, and I tested all the outlets
which seem to work fine

(i am due for inspection)

having some geeky background I looked at the open sub-panel,
it only has 3 wire service two-hots and a neutral (and no ground)

Upon further inspection, I see that the electrician has run the
green GROUND wire directly from main panel to new outlets,
and the hot/neutral from sub-panel.

Questions:

1) is this code compliant?
2) is this standard practice?

I understand that the ground and neutral at the sub-panel should not be bonded but having no ground at the sub-panel has me confused

Thank you
 
Is the installation done in metallic pipe?

If this is a new sub panel than an equipment ground conductor should have been run with the feeder wires. If this is fed with metallic conduit then the ground exists throught the conduit.

Why they would run the EGC back to the main panel without installing a ground is beyond me.
 
Two questions back at you:
(1) Is it possible that the raceway from the main panel to the sub panel can be credited as being an EGC?

(2) Are any of the receptacle circuits installed as "multi-wire branch circuits"? That is, do you have a two-pole breaker (or a pair of single pole breakers) feeding a set of receptacles with the neutral wire shared between the two?

Even if the answer to (1) is "yes," then there should still have been a ground bar in the sub panel.

If the answer to (2) is "yes," then you have a violation of 210.4(a).
 
I see that Dennis was posting while I was typing. :grin:

Having read further into the code, let me now add the opinion that the fact that they ran EGCs from the main panel created a violation of 408.40.
 
Are these isolated ground receptacles? Their EGC's are permitted to run back to the main service.
 
charlie b said:
Two questions back at you:
(1) Is it possible that the raceway from the main panel to the sub panel can be credited as being an EGC?

(2) Are any of the receptacle circuits installed as "multi-wire branch circuits"? That is, do you have a two-pole breaker (or a pair of single pole breakers) feeding a set of receptacles with the neutral wire shared between the two?

Even if the answer to (1) is "yes," then there should still have been a ground bar in the sub panel.

If the answer to (2) is "yes," then you have a violation of 210.4(a).
Click to expand...


thanks folks excellent info and you have asked the correct questions:

1) yes the raceway is metallic, and its being used as EGC
2) there is one 110/208 device (dish washer) that uses two-pole breaker,
here the electrician has run a green ground wire from the panel ground bar to the outlet (total 4 wires).

Now I am armed and equiped to handle the city inspections....

Thank you! You guys know what you're doing....
 
charlie b said:
I see that Dennis was posting while I was typing. :grin:

Having read further into the code, let me now add the opinion that the fact that they ran EGCs from the main panel created a violation of 408.40.
Click to expand...

oops,

I just read this post, in this case is the best solution to create EGC by connecting the conduit to the building ground? ( I need to check if this is done already, I had assumed that the EGC is grounded at the main panel).

Thanks again.

=B. Bhatt=
 
The conduit is automatically grounded to the panel if all the connectors and couplings are made tight--- That is assuming the main panel is bonded properly. Many EC install an EGC to insure a better ground in case someone didn't tighten a coupling well enough. Some specs actually call for it.
 
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