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#114716 - 06/12/03 01:26 PM Chillers
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This is a configuration I found on a new chiller set up. There is a 400 amp feeder that comes from the MDP in a separate room, it comes into a large Hoffman box, someone mounted 2 sets of 200 amp fuses, and ran to the two chillers.

No disconnecting means in either the box or the control cabinet.
Check out the greenfield supports on the 2nd chiller, and the control wiring coming down into the enclosures from above.

George Corron

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#114717 - 06/12/03 05:46 PM Re: Chillers
Bjarney Offline
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Ho-lee sheep sh!t. Someone actually tried this to “save” $200 for flange-mount breaker operators in the control panels?

To top it off, the convenient load-on-top fuse wiring is priceless. That spartan, no-ugly-label motif is to die for. (An “extra-mile” feature would have been a set of chained-down loadbreak fuse pullers. ;-)

These shots should qualify for the annual Hoffmann “bloopers” calendar.




[This message has been edited by Bjarney (edited 06-12-2003).]

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#114718 - 06/12/03 06:01 PM Re: Chillers
George Corron Offline
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Registered: 05/16/01
Posts: 728
Loc: Lorton, Va USA
Bjarney,
And before anyone asks, no the breaker in the other room is a normal handle breaker, not readily lockable. Fortunately, I may have caught this in time to force the contractor to repair instead of my crews.

Check out the extra fancy greenfield support, ya know, it don't get no better than air, it don't rust, or cause no trouble _

The control circuitry coming into the top of the cabinets goes up about 10' to the ceiling with no supports as well.

Cool, huh?

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#114719 - 06/12/03 10:03 PM Re: Chillers
wolfdog Offline
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Registered: 10/24/01
Posts: 135
Loc: Dallas,TX
Maybe it's a package deal......buy a sorry McQuay chiller and get sorry electrical work.

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#114720 - 06/12/03 10:11 PM Re: Chillers
Bjarney Offline
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Loc: West-Southern Inner-Northeast ...
George, I may have goofed. At first glance, the middle shot of the open chiller controller panel looks like a reach-inside, not-externally-operable molded-case breaker at 9 o’clock—is it a contactor?

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#114721 - 06/12/03 11:27 PM Re: Chillers
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#114722 - 06/13/03 04:16 AM Re: Chillers
George Corron Offline
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Registered: 05/16/01
Posts: 728
Loc: Lorton, Va USA
Bill's close-up shows a bit more detail. The object you see inside is a contactor only, there is NO disconnecting means inside the cabinet........ or outside for that matter. The only way to work on one would be to turn off the 400 amp breaker in the other room (no ready way to lock or tag out), remove the 3 fuses of the affected unit, and then reenergize.

Wolfdog, not familiar with the reputations of chiller equipment, I take it you don't like McQuay? Personal experience?

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#114723 - 06/13/03 07:13 AM Re: Chillers
Bjarney Offline
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Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
Apologies for mistaking the contactor for a breaker. The chiller control cabinet has an nice right-side front flange that seems could accommodate a traditional motor-control-type disconnect switch or circuit-breaker operator. They are made by Allen-Bradley, Square-D, Cutler-Hammer, and others.

So then, my idea of a set of chained-down loadbreak ;-) fuse pullers didn’t get any votes? {Sorry...I couldn’t resist! Refrigeration designers do come up with some doozies on occasion.}

It’s unfortunate when a facility owner and maintenance crew inherit that kind of “creativity” for the next 30 years.




[This message has been edited by Bjarney (edited 06-13-2003).]

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#114724 - 06/13/03 12:34 PM Re: Chillers
wolfdog Offline
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Registered: 10/24/01
Posts: 135
Loc: Dallas,TX
McQuay bought the Westinghouse centrifugal line some years back and did not improve on it.
The reciprocating equipment is weird also.


McQuay is commonly refered to as McCrap and Mcjunk.

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#114725 - 06/13/03 08:19 PM Re: Chillers
resqcapt19 Offline
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Registered: 11/10/00
Posts: 2209
Loc: IL
George,
What did the specs call for? Was the chiller equipment to be supplied with disconnects by the manufacturer or was the contractor required to provide the disconnects?
By the way, even if the breaker in the next room was lockable, it would not meet the code requirements. 430.102(A) requires a disconnect within sight of the controller. There are no exceptions to 410.102(A) like there are for 102(B).
Don
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Don(resqcapt19)

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