EGC in partially renovated dwelling unit (old residential 12-floor building)

[victor.cherkashi]

Existing wiring in dwelling unit is hot + neutral, no EGC.
Several new branch circuits are required. Based on my understanding of the NEC, new branch circuit must have EGC.

1. Where you supposed to connect EGC of MC cable if the panel does not have EGC bus-bar?
2. Is there any way to prevent a replacement of existing panel?

 

[LarryFine]

Based on my understanding of the NEC, new branch circuit must have EGC.

Correct. All new wiring must conform to present requirements.

1. Where you supposed to connect EGC of MC cable if the panel does not have EGC bus-bar?

You'll need to add one, as long as the enclosure is properly bonded.

2. Is there any way to prevent a replacement of existing panel?

I'd have to see it and have you explain why you think it may need to be.

 

[victor.cherkashi]

Correct. All new wiring must conform to present requirements.


You'll need to add one, as long as the enclosure is properly bonded.


I'd have to see it and have you explain why you think it may need to be.

Thank you for prompt response

2. I thought that we are not supposed to add anything inside panel box unless it is permitted by manufacturer specification, this is why I thought about replacement of the existing panel.
3. Is there a section in NEC that specifically permit installation of bus-bar inside existing power panel (assuming there is enough space for bus-bar and wiring)? I will try to search this in NEC.

 

[LarryFine]

It's done all the time. Use tapping bolts or bolts into threaded holes, not sheet-metal screws.

If you have a picky inspector, use the same brand bus bar as the panel, if you can find one.

 

[Fred B]

If it is your main panel (not a subpanel) you may not see a seperate ground bus, check for the location of your GEC, you would likely see it tied to your neutral bus. You can then land your new circuit grounds right there. If it is a subpanel the GEC may have just been bonded to box. If that is the case as already mention you can add a ground bar, just be sure neutral was not bonded to enclosure if a subpanel.

 

[don_resqcapt19]

It's done all the time. Use tapping bolts or bolts into threaded holes, not sheet-metal screws.

If you have a picky inspector, use the same brand bus bar as the panel, if you can find one.

You have to be careful with that...the metal on many enclosures is not thick enough to engage two threads unless you are installing the bolts into factory punched holes intended for that purpose. When they punch those holes, the pull a lip to the outside that effectively increases the wall thickness so that two threads are engaged in the metal. If you don't have two threads engaged, you need a nut on the back side.