Transformer GEC. Beat a dead horse time

[82angelfan]

I am installing several dry type transformers in a new electrical room. We installed a buss bar in electrical room and attached it to the Shell and Core Grounding system, which is attached to Ufer and Building steel.

I brought my GEC for each transformer from my buss bar to a ground buss in the Transformer installed by factory. My G.F. says the inspector will call us on it because we did not hit the X0 first. I told him I will change it but I also remember an engineer telling me, while doing an inspection, that it is a common misconception .
Below are figures and codes out of the code book. The figure specifically shows GEC going to ground buss, then a ground going to X0.

Any thoughts on this. Is there specific wording that says you must hit the X0 first.

 

[hillbilly1]

You do not have to hit XO first, but you need the appropriate size jumper from XO to the ground bar that has the GEC.

 

[LarryFine]

You are correct. X-0 may be bonded through an appropriately-sized conductor jumper.

 

[82angelfan]

You are correct. X-0 may be bonded through an appropriately-sized conductor jumper.

I've always sized my transformer GEC to my secondary size conductors and 250.66. However this single line has specific GEC sizes called out. They are all one size bigger.

 

[infinity]

Any thoughts on this. Is there specific wording that says you must hit the X0 first.

The graphic shows one way to do it. Note the terminal bar in the graphic can actually be the section of bus that it typically part of the X0.

 

[Elect117]

The GEC should land at the same location as the SBJ, and I don't know if you are referring to the transformer case or the transformer's frame (usually bonded by a strap). The strap is typically installed by factory but the terminal kit is usually shipped in a baggy. So I guess I am a little confused by that.

I would add that another common misconception is to use the transformers case to bond the various connections made between the SBJ, GEC, SSBJ, and EGC. The case can not be used as a jumper or method of bonding the various connections. It must be made at a terminal bar, bus or be of a wire type. Also see 450.10.

A lot of times the terminal kits they sell with the dry type are not sufficient for all of the connections if you do not run one wire for the GEC, to the X0, to the terminal kit, to the panel board (with any bonding type lock nuts) as one wire with no splices. Then the only other connection left is the EGC for the primary side.

Most of the time, you will need to buy an additional terminal kit (like those made for panel boards).

 

[82angelfan]

The GEC should land at the same location as the SBJ, and I don't know if you are referring to the transformer case or the transformer's frame (usually bonded by a strap). The strap is typically installed by factory but the terminal kit is usually shipped in a baggy. So I guess I am a little confused by that.

I would add that another common misconception is to use the transformers case to bond the various connections made between the SBJ, GEC, SSBJ, and EGC. The case can not be used as a jumper or method of bonding the various connections. It must be made at a terminal bar, bus or be of a wire type. Also see 450.10.

A lot of times the terminal kits they sell with the dry type are not sufficient for all of the connections if you do not run one wire for the GEC, to the X0, to the terminal kit, to the panel board (with any bonding type lock nuts) as one wire with no splices. Then the only other connection left is the EGC for the primary side.

Most of the time, you will need to buy an additional terminal kit (like those made for panel boards).

There is a terminal bar factory installed in these transformers sufficient for a jumper from X0 to terminal, EGC from primary, EGC from secondary, as well as GEC from ground buss in electrical room.

 

[electrofelon]

.

A lot of times the terminal kits they sell with the dry type are not sufficient for all of the connections

And this drives me crazy. Happens in enclosed circuit breakers and safety switches too. Must be the same people that made or approved the sharp corners on the PVC LB's. Clueless.