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#213567 06/03/14 08:25 PM
Joined: Apr 2002
Posts: 7,381
Likes: 7
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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.



John
Joined: Dec 2000
Posts: 4,294
Member

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.



Joined: Jul 2004
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G
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Electrically I suppose it is fine assuming you have overcurrent protection somewhere else.

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



Greg Fretwell
Joined: Oct 2000
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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)


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Joined: Jul 2004
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G
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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


Greg Fretwell
Joined: Apr 2002
Posts: 7,381
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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?



John
Joined: Apr 2002
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Electure:
Thanks for the link.



John
Joined: Jul 2004
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G
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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)



Greg Fretwell
Joined: Apr 2002
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Bump.....


John

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