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Posted By: HotLine1 Convert a fused pull out??? - 06/04/14 12:25 AM
Opinions please gentlemen:

Can a fused pullout disconnect be converted to a non-fused disconnect??

ie: replace the fuses with 1/2" copper pipe.

I'm interested in opinions from any and all of you guys.

Posted By: electure Re: Convert a fused pull out??? - 06/04/14 01:55 AM

Bussman has a product just for this application:

http://www.cooperindustries.com/con...eutrals_.catalog_numbers_%28amps%29.html

(It looks like a piece of 1/2" brass pipe) laugh

I'd use this instead of copper pipe.


Posted By: gfretwell Re: Convert a fused pull out??? - 06/04/14 05:37 AM
Electrically I suppose it is fine assuming you have overcurrent protection somewhere else.

How do you feel about "approving" unlisted products? (110.2)

Posted By: Scott35 Re: Convert a fused pull out??? - 06/04/14 03:07 PM
The "Dummy Fuses" referenced in Electure's posted Hyperlink, are useful in 3 Pole Safety Switches; where the System used is a 3 Phase 3 Wire Corner Grounded Delta.

This effectively opens all 3 Conductors (both Ungrounded Conductors and the Grounded Conductor) simultaneously, and keeps the Grounded Conductor "Solid" (No OCPD in Series) at the Disconnect / Safety Switch.

Footnote: When such an item is seen by "4 Wire Wye-Guys only", the reactions by those unfamiliar with Corner Grounded Systems range from a simple "Whaddaheck???" to "Evacuate The Building!!!"

After which comes the difficulty of trying to explain why the Identified (i.e. Grounded) Conductor is One of the Three Wires for this 3 Phase 3 Wire Branch Circuit - and why White or Gray Insulation / Tape on this Conductor is Code Compliant...

Most grasp the concept and accept the System's "Differences", while only a few (be they obnoxious, arrogant, or simply from Mule-Level Reluctance), refuse to accept any part of such an Alien System's use, operation and Code Compliance.
(Note: I mention the latter, due to a few ugly debates from past installations...)

--Scott (EE)
Posted By: gfretwell Re: Convert a fused pull out??? - 06/04/14 06:42 PM
The corner grounded systems I saw, (all sewer lift pumps) used equipment like single phase with two ungrounded conductors in a 2 pole breaker and a white grounded conductor with no overcurrent protection or disconnecting means at all.
If there was a switch type disconnect, it was 2 pole.

I admit, the first one I saw, standing there all alone with no help around had me pretty confused for a minute
I am glad I had heard of corner delta and was glad I figured it out before I said something dumb. wink
Posted By: HotLine1 Re: Convert a fused pull out??? - 06/04/14 07:53 PM
Greg:
Yes, there was OCP back at the breaker panel, amperage conforming to the mfg nameplate. (HVAC-CU)

The old disco is marked 'fuses within pullout'. This is on an engraved plate on the disco.

I know electrically it works, however IMHO copper pipe is not a fuse.

The installer left a message that he is looking for a 'solid' pullout. I thought good luck; the disco is 60s vintage. I think two 30 amp, 250 volt, TD fuses will be a lot cheaper and easier to find?

Posted By: HotLine1 Re: Convert a fused pull out??? - 06/04/14 07:55 PM
Electure:
Thanks for the link.

Posted By: gfretwell Re: Convert a fused pull out??? - 06/05/14 06:22 AM
Like I said it is only OK if you approve unlisted fuse replacements. I agree with you. Bussman makes one so they should be using that. (or just put in some real fuses)

Posted By: HotLine1 Re: Convert a fused pull out??? - 06/10/14 01:39 PM
Bump.....
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