Grounding electrode for 300kva XFMR

[RickyBobby]

I recently moved a 300kva XFMR from the 2nd floor, of a office building, to the first floor, because a dentist complained that it was too loud. I ran the 3/0 GE to a 2" water line just outside the electric room above a grid ceiling. The inspector failed me, saying, I need to run the GE within 5' of the point of entry and I need to run a jumper from the 1st floor water line to the 2nd floor water line. I sighted 250.68(c) exception and he said its above a ceiling and not "exposed" (Art. 100 definitions; Exposed (as applied to wiring methods) ...or behind panels designed to allow access), He said this is not wiring methods. Than he stated 250.104(d)(1), "in the area served by..." so I need to take GE to the second floor as well. This came from the senior electrical inspector at the Pikes Peak Regional Building Dept.

 

[ActionDave]

Where is your secondary disconnect?

Where is the XO bonded?

 

[RickyBobby]

The secondary feed a 800a breaker in a panel next to the XFMR. XO bond is in the XFMR (3/0). The (3) panels on the second floor is fed by (2) 300a breakers and (1) 200a breaker from the 800a panel.

 

[ActionDave]

I can see him requiring the GEC to within five feet of the water line entering the building. I do not agree with running a jumper to the second to the second floor.

 

[petersonra]

I can see him requiring the GEC to within five feet of the water line entering the building. I do not agree with running a jumper to the second to the second floor.

Take a look at 250.104(D)(1) regarding bonding of the piping system on the second floor. I think he is right, but maybe not for the right reason.

 

[ActionDave]

He's got his connection to the metal water pipe to the sds at his transformer.

 

[RickyBobby]

Take a look at 250.104(D)(1) regarding bonding of the piping system on the second floor. I think he is right, but maybe not for the right reason.

I read that article a few times and I believe this is were we have our discrepancies. When it states, "bonded to the nearest available point of the metal water piping system(s) in the area served by each separately derived system." I believe when it says "served" it means the feed for the XFMR. If the code wants me to bond to the second floor water, I think it should read "in the area the separately derived system is serving". It seems impractical to run all that distance. Let me your thoughts.

 

[ActionDave]

Each separately derived system would be each transformer if you had more than one. It could be generators, or any combination.

It does not mean each sub panel served by a transformer. That would be ridiculous.

There's no way

 

[ActionDave]

Art. 100 definition

Separately Derived System.

An electrical source, other than a service, having no direct connection to circuit conductors of any other electrical source other than those established by grounding and bonding connectconnections.

There's no way that includes the panel on the second floor.