Feeding old all in one from new

K

kgw

Member
Location
AZ
Occupation
Electrical Contractor
Seeking input...AHJ is allowing what I suspect may be a NEC violation. Am removing existing 200 Amp overhead utility service to CSED ("all-in-one"?). Installing new 200 Amp CSED and overhead service, 22 kW generator, and 200 Amp ATS. Existing CSED to be fed from ATS. Existing CSED neutral appears to have integral bond; branch circuit grounding and neutral conductors are terminated on same ground bars.
I proposed installing new insulated neutral bar kits in existing all in one, connected to bonded neutral in new CSED. with all existing branch neutrals terminated on new insulated neutral bars (leaving grounding conductors on existing ground bars). In that scenario,
neutral in new all in one would be grounded, abd bond at existing all in one would be elimimated.

AHJ will accept leaving existing all in one as-is (neutral bonded), fed from new all in one.
Seems to me that would create a parallel neutral path between old & new all in one.
TIA for input.
 
I'd make the ATS my service disconnect and just buy a regular meter base, no need for another meter/main, Group the meter base outside, and ATS is now your service disconnect, move all grounding and bonding to it.
I would rip out and replace the old meter/main with a new main lug panel and supply it with a new 4-wire feeder.
 
Wish I could figure out how to post a pic.
CSED = Combination Service Entrance Device, aka all-in-one. My plan is for the existing CSED to remain but become a sub panel fed from new CSED via ATS. Hope to reuse existing CSED to simplify the project, avoid reworking existing circuits. The issue is whether it's ok to have the neutral bonded at both CSED's.
ActionDave said:
Welcome to the forum.

You said you are removing an existing CSED and installing a new CSED. You also say that an existing CSED is being fed from a new transfer switch. How many of them are there on this project? What is a CSED?
Click to expand...
ActionDave said:
Welcome to the forum.

You said you are removing an existing CSED and installing a new CSED. You also say that an existing CSED is being fed from a new transfer switch. How many of them are there on this project? What is a CSED?
Click to expand...

ActionDave said:
Welcome to the forum.

You said you are removing an existing CSED and installing a new CSED. You also say that an existing CSED is being fed from a new transfer switch. How many of them are there on this project? What is a CSED?
Click to expand...
 
CSED = Combination Service Entrance Device. No one here calls them that, we call them meter/mains with or without distribution

What you are proposing would be a violation more than likely. The best solution is use a meter/main/ATS/distribution, like what Generac is offering.

Second best is meter - SE-Rated ATS - distribution/sub panel. The only N-G bonding that should take place would be in the ATS.

Another possible issue with your scenario is if the existing main with distribution is listed as Only For Use as Service Equipment, it’s technically a violation to reconfigure that as a sub panel.
 
Seven-Delta-FortyOne said:
What you are proposing would be a violation more than likely. The best solution is use a meter/main/ATS/distribution, like what Generac is offering.

Second best is meter - SE-Rated ATS - distribution/sub panel. The only N-G bonding that should take place would be in the ATS.
Click to expand...
I may be the only electrician that doesn't like to use a transfer switch as a service disconnect.
 
kgw said:
Seeking input...AHJ is allowing what I suspect may be a NEC violation. Am removing existing 200 Amp overhead utility service to CSED ("all-in-one"?). Installing new 200 Amp CSED and overhead service, 22 kW generator, and 200 Amp ATS. Existing CSED to be fed from ATS. Existing CSED neutral appears to have integral bond; branch circuit grounding and neutral conductors are terminated on same ground bars.
I proposed installing new insulated neutral bar kits in existing all in one, connected to bonded neutral in new CSED. with all existing branch neutrals terminated on new insulated neutral bars (leaving grounding conductors on existing ground bars). In that scenario,
neutral in new all in one would be grounded, abd bond at existing all in one would be elimimated.
Click to expand...

I discovered a new service done like this recently. It was a real hack job because they took out the original main breaker to make space for the new isolated neutral bar. I don't recommend this because your typical meter/main isn't designed with enough space to shoehorn in an isolated neutral bar. It may also be a 110.3(B) violation. More power to you if you can do it cleanly meeting all wire bending space rules and the AHJ signs it off. I can't see how it looks from here anyway.

AHJ will accept leaving existing all in one as-is (neutral bonded), fed from new all in one.
Seems to me that would create a parallel neutral path between old & new all in one.
TIA for input.
Click to expand...

Well this is also wrong. In fact it's more wrong by the NEC on the face of it. Might look cleaner and be cleaner but has a clear and obvious NEC violation we can see from here.
 
Technically it is a violation. But I don't see the harm if everything is close together. You can have an Emergency Disconnect marked not service equipment that feeds a bonded service panel which is effectively the same thing. That option is going to go away though in the future. If you have a separate meter with metal conduit to the service disconnect, that conduit has service neutral current on it and no one thinks twice about it.

AHJ sounds like they are accommodating.
 
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