ECN Forum Forums General Topics of the Trade General Discussion Area Convert a fused pull out???

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.

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)

I'd use this instead of copper pipe.

Electrically I suppose it is fine assuming you have overcurrent protection somewhere else.

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

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)

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.

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?

Electure:
Thanks for the link.

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)

Bump.....