# CT Cabinet



## A/A Fuel GTX (May 6, 2009)

Does a CT Cabinet typically use a main bonding jumper for grounding the enclosure like a meter socket does?


----------



## mbednarik (Oct 10, 2011)

Your average meter socket has the neutral permanently bonded to the case, where most CT cabinets require a bonding wire to be run from the grounded conductor to the grounding terminal. This is called you supply side system bonding jumper.


----------



## A/A Fuel GTX (May 6, 2009)

mbednarik said:


> Your average meter socket has the neutral permanently bonded to the case, where most CT cabinets require a bonding wire to be run from the grounded conductor to the grounding terminal. This is called you supply side system bonding jumper.


So there is a mechanical lug mounted to the enclosure that is connected to the neutral bar via a conductor based on 250.66? The reason I'm asking is I looked at a 600A CT Cabinet and the main bonding jumper kit was optional. Some time ago, I saw an install that had no neutral to can connection but rather an EGC run from the MDP that the CT Cabinet fed.


----------



## mbednarik (Oct 10, 2011)

As long as the jumper beween the MDP and the CT was sized using 250.66, either way is code compliant. I have always bonded the grounded conductor and the can. I usually use Galva CT cabinets and they have a lug connected to the case.


----------



## wildleg (Apr 12, 2009)

it depends on your utility. the blue book generally specifies what is or isn't allowed for grounding. I don't think I've seen a bonding jumper inside a CT. some utilities here don't allow any ground wires in the CT cabinet.


----------



## Vic098 (Oct 27, 2012)

wildleg said:


> it depends on your utility. the blue book generally specifies what is or isn't allowed for grounding. I don't think I've seen a bonding jumper inside a CT. some utilities here don't allow any ground wires in the CT cabinet.


When I first got out of school I was a "helper" for an EC who did a lot of work in NJ. The job was in PSE&G jurisdiction. The mechanic made the bond in the CT and the utility said NO. We had to take it apart and make the bond inside.
I don't recall seeing the bond made in a CT since then.


----------



## wendon (Sep 27, 2010)

Not sure why they stopped doing it but I think it had something to do with being able to inspect the bond without having to remove the tag on the CT or meter socket. Years ago one of the utilities around here installed the ground rods and connected the GEC in the meter can but the only one that I know that does it now is one of the local cities.


----------



## icefalkon (Dec 16, 2007)

I would advise you to go online, check out your local utilities Blue Book. You usually can download the PDF files. 

Or...just call them and ask if it is required in your jurisdiction. 

Good luck.


----------



## brian john (Mar 11, 2007)

Vic098 said:


> When I first got out of school I was a "helper" for an EC who did a lot of work in NJ. The job was in PSE&G jurisdiction. The mechanic made the bond in the CT and the utility said NO. We had to take it apart and make the bond inside.
> I don't recall seeing the bond made in a CT since then.


All our CT cabinets come with the neutral mounted to the back box.


----------



## A/A Fuel GTX (May 6, 2009)

brian john said:


> All our CT cabinets come with the neutral mounted to the back box.


As in the way a standard 200/320A meter socket is? If the neutral bar in the CT cabinet does not have a connection to the enclosure, then an EGC must be run from the MDP to the cabinet and that sounds like the less preferred way to do it to me. This has nothing to do with the grounding electrode conductor as that can be terminated at the first disconnect as normal.


----------

