UL98 vs UL508

[conmgt]

I have a question about installing a disconnect on the primaries to a transformer. I'm also going to put a contactor after the disconnect and before the transformer. I have another post going concerning the contactor.
Due to space limitations, I'd really like to put the disconnect and contactor in a hinged and paneled enclosure but I'm confused on what is allowed to be used as a disconnect.

A safety switch is UL98 and seems to be an acceptable disconnect under many applications. A UL508 seems to have limitations. I'm finding a few good candidates for fitment in an enclosure but am concerned that since they are rated UL508, they may not be acceptable. Specifically, SqD's Vario UL508 Motor Disconnect Switches. Does the term motor in the name or the UL508 listing automatically disqualify it? And then there's the GV7 Manual Starter and Protector UL508 approved and mountable in an enclosure.

http://products.schneider-electric....ductDetail&partNumber=GV7RS100&countryCode=us

http://products.schneider-electric....-breaker-mechanisms/vario-loadbreak-switches/

Any thoughts, insight, or suggestions?

 

[conmgt]

Here's an interesting article on 98 vs 508:

http://www.plantservices.com/industrynews/2008/044.html

 

[conmgt]

It looks like the last page of this:

http://www.barr-thorp.com/wp-content/uploads/2011/06/UL-508-Application-Guide.pdf #3 Common Misapplications.

answers my question.

 

[conmgt]

I think page for has the product that I need.
http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/19024778622281db8525777300744f9d/$file/1sxu301077b0203.pdf

I sent them an e-mail to check.

 

[Jraef]

Simple way to look at it:

If there IS already a UL98 fused disconnect or a UL489 circuit breaker ahead of this as BRANCH circuit protection (meaning just for this circuit), then a UL508 disconnect is OK. If not, you cannot use it.

Or another way: A UL508 rated disconnect can only be the SECOND one in a circuit, but never the first one.