bonding when grnd wire is pulled

[marpar]

I am installing a 60 amp 480 volt disconnect in our factory that feeds (3) 30 amp 480 volt disconnects for feeds to 3 battery chargers. The 60 amp disconect is being fed from a factory buss plug system that feeds all sorts of equipement. A co-worker & I got into a disagreement on weather bonding bushings should be used since we pulled a ground conductor thru-out the system & grounded it at each disconnect & ties directley back at the bussway system. I said it wasn't necesary since we are not using the conduit as a ground. we are using siemens fuseable disconnects with eccentric k.o.'s with double locknuts & ridgid conduit pipe. they are mounted on metal framing with multiple grounding contacts thru-out. The way I understand the NEC book is that it is nit neccesary when the pipe, raceway, etc. is not being used as a grounding system. please help. Marty

 

[Cow]

Same question asked here:

http://forums.mikeholt.com/showthread.php?t=151500&p=1463621&posted=1#post1463621

 

[augie47]

In my opinion, the presence of a wire for an equipment grounding conductor does not relieve you from having to meet the requirements of 250.96 and some approved bonding means would be needed when encountering eccentric or concentric knockouts unless the enclosure was listed as not requiring a bonding means.

 

[kwired]

In my opinion, the presence of a wire for an equipment grounding conductor does not relieve you from having to meet the requirements of 250.96 and some approved bonding means would be needed when encountering eccentric or concentric knockouts unless the enclosure was listed as not requiring a bonding means.

I agree.

 

[iwire]

In my opinion, the presence of a wire for an equipment grounding conductor does not relieve you from having to meet the requirements of 250.96 and some approved bonding means would be needed when encountering eccentric or concentric knockouts unless the enclosure was listed as not requiring a bonding means.

I also agree and will add that the eccentric KOs in disconnect enclosures are not listed for bonding.

 

[guschash]

I agree, too. With or without petty well somes it up I think.

 

[wirebender]

I also agree and will add that the eccentric KOs in disconnect enclosures are not listed for bonding.

How about the concentric?

Where would I find this info?

 

[Dennis Alwon]

Here is something I found by UL at this site

Bonding for Over 250 Volts
For bonding circuits over 250 volts, NEC Section 250.97 is applicable, and by exception, allows concentric and eccentric knockouts to be used without bonding jumpers, provided the box or enclosure with concentric or eccentric knockouts is listed to provide a reliable bonding connection. This is where the UL White Book comes into play.

For the UL product category for Metallic Outlet Boxes (QCIT), the UL Guide Information indicates “All boxes with concentric or eccentric knockouts have been investigated for bonding and are suitable for bonding without any additional bonding means around concentric (or eccentric) knockouts where used in circuits above or below 250 V, and may be marked as such.”

Please refer to the UL White Book for this product category, or view this information online at www.ul.com/database. Enter
“QCIT” into the database field for “UL Category Code.

 

[kwired]

Here is something I found by UL at this site

That only mentioned metal outlet boxes though, Bob mentioned disconnect enclosures. I could be wrong but thought some were designed to not require additional bonding and was even more likely if the eccentric type.