AC Cable to NM (ROMEX®)

**mrhoades** · 01-30-2009, 03:29 PM

My house built in the late 40's uses old BX cable (no bonding strip) and an 1980's renovation using AC cable w/the bonding strip. I would like to begin finishing my basement.... Am I allowed to add new circuits using NM (ROMEX®). If so how do I ground inside the fuse box?

**jwelectric** · 01-30-2009, 04:19 PM

If an armored cable is being used I hope that there is a metal box also. The equipment grounding conductor of the NM cable bonds to this metal box

**RayP** · 01-31-2009, 04:50 PM

You can as long as you have the correct ground. Easy way to do this is replace your box and grounding electrode, and also the service cable. This sounds hard but is not. You can pay to have an electrician do it for $500-$1000, where I am (upstate NY). Homeowners can do it themselves here, after claiming to have the skill. You then need to have it inspected before cut in by the utility company.

**jwelectric** · 01-31-2009, 06:51 PM

Originally Posted by RayP

You can as long as you have the correct ground. Easy way to do this is replace your box and grounding electrode, and also the service cable. This sounds hard but is not. You can pay to have an electrician do it for $500-$1000, where I am (upstate NY). Homeowners can do it themselves here, after claiming to have the skill. You then need to have it inspected before cut in by the utility company.

Why would you need to do all this just to convert from AC to MN?

**GabeS** · 02-01-2009, 09:22 AM

The old armored cable without the bonding strip: That stuff is grounded. When I test that wiring it shows ground.

Is it not allowed to connect new bx to the old?

**Chris75** · 02-01-2009, 09:31 AM

This thread should be a good one...

**Chris75** · 02-01-2009, 09:33 AM

Originally Posted by GabeS

The old armored cable without the bonding strip: That stuff is grounded. When I test that wiring it shows ground.

Is it not allowed to connect new bx to the old?

If the AC cable does not contain a bonding strip then you cannot use the jacket as an equipment ground, nor extend those circuits with NM. Just start installing new circuits with NM back to the panel. Which I believe was your orginal question to begin with, Inside the panel the grounds and neutral conductors tie to the same bus.

**Chris75** · 02-01-2009, 09:34 AM

Originally Posted by RayP

You can as long as you have the correct ground. Easy way to do this is replace your box and grounding electrode, and also the service cable. This sounds hard but is not. You can pay to have an electrician do it for $500-$1000, where I am (upstate NY). Homeowners can do it themselves here, after claiming to have the skill. You then need to have it inspected before cut in by the utility company.

I dont know why your suggesting any of that...