Adding conductors to a full transformer secondary

[sceepe]

Here's the situation. An addition to an existing building requires a new main. The existing POCO pad mount has the KVA capacity but no space for additional secondary conductors.

POCO recommends we install a "secondary tap box" which I gather is just a box with buss bars for adding additional secondary conductors. I nor my electrician have ever seen such a thing.

1. Does anybody know who makes these?
2. (to keep with the rules of the forum) do the conductors between the transformer and the "secondary tap box" need to be protected?

 

[jtester]

Re: Adding conductors to a full transformer secondary

Our utility has a similar requirement, and among others we use an EASTER-OWENS bus bar enclosure. In our case, the utility runs the conductors between the transformer and the enclosure, and we run from it to the service equipment. I see no reason for the conductors between xfmr and enclosure to be protected on the line side.
Jim T

 

[jim dungar]

Re: Adding conductors to a full transformer secondary

Many of the "CT cabinet" manufacturers also make utility approved tap boxes. Common ones in our area are Erickson and Galva-Closure

 

[dnbob]

Re: Adding conductors to a full transformer secondary

AMP - American Midewest Power - makes a great cross connect cabinet as we call them. No need for overcurrent protection, just a bonding jumper inside from the neutral to the frame of the enclosure. We are required to pull the wire between the cabinet and transformer as well as the secondary to the service.

 

[steve66]

Re: Adding conductors to a full transformer secondary

Here is a link to Erickson:

Erickson Tap Boxes

Cooper also makes them.

Since it it a Utility transformer, you will have to check with them and your AHJ to see if you need OCP on the line side of the tap box.