NEC 460 CAPACITOR OIL ISSUE

[Jim Hughes]

I have a question on Article 460.1 and 460.2 in regards to power factor correction capacitors and the dielectric oil used in these capacitors.

We are a OEM manufacture of power factor correction equipment and I have a client spec calling out the following pertaining to medium voltage capacitors and dielectric fluid used in capacitors.

Client spec is as follows.

?Installation shall comply with the latest edition of the National Electric Code Article 460 and shall meet the NEC indoor installation requirement for having less than three gallons of dielectric fluid.?

Our equipment would use six capacitors each containing 3.3 gallons of fluid. The capacitors would be assembled with other equipment inside a metal enclosed enclosure for indoor service. Access is guarded by lock and key.

In reading Article 460.1 Scope, NEC states the following ?Surge capacitors or capacitors included as a component part of other apparatus and conforming with the requirements of such apparatus are excluded from these requirements.?

Since we are using the capacitors as components of a system and build to standards for this type of equipment, I read the NEC 460.1 Scope as we are excluded from these requirements. Can anyone shed some light on this and let me know if I?m correct in what I read from NEC.

Thanks in advance for your help.

Regards

Jim Hughes
Power Survey

 

[charlie b]

Re: NEC 460 CAPACITOR OIL ISSUE

I'll agree that each of your capacitors is a component part of a larger apparatus. But 460.1 says that each of the capacitors must conform with the requirements that apply to the larger apparatus. So what is that larger apparatus, and what requirements would apply to it? It seems to me that it is a capacitor bank, and the requirements that would apply are the requirements of 460. In other words, I don't think you are excluded from 460.

 

[jim dungar]

Re: NEC 460 CAPACITOR OIL ISSUE

I believe your installation is subject to 460. Your capacitors are not an [ancillary] component of an apparatus, they are the apparatus. I see your PF controlling equipment as the component of the capacitor bank.

460.2(A) mentions multiple capacitors.
460.6(B), 460.8(B), and 460.8(C) include requirements for capacitor banks.

edit: typos

[ August 31, 2005, 12:14 PM: Message edited by: jim dungar ]