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#114716 06/12/03 04:26 PM
Joined: Oct 2000
Posts: 3,682
Likes: 3
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[Linked Image]

[Linked Image]

[Linked Image]
Quote
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

#114717 06/12/03 08:46 PM
Joined: Apr 2002
Posts: 2,527
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Moderator
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).]

#114718 06/12/03 09:01 PM
Joined: May 2001
Posts: 717
G
Member
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 [Linked Image]_

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

Cool, huh?

#114719 06/13/03 01:03 AM
Joined: Oct 2001
Posts: 135
W
Member
Maybe it's a package deal......buy a sorry McQuay chiller and get sorry electrical work.

#114720 06/13/03 01:11 AM
Joined: Apr 2002
Posts: 2,527
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Moderator
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?

#114721 06/13/03 02:27 AM
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Closeup:

[Linked Image]

#114722 06/13/03 07:16 AM
Joined: May 2001
Posts: 717
G
Member
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?

#114723 06/13/03 10:13 AM
Joined: Apr 2002
Posts: 2,527
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Moderator
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).]

#114724 06/13/03 03:34 PM
Joined: Oct 2001
Posts: 135
W
Member
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.

#114725 06/13/03 11:19 PM
Joined: Nov 2000
Posts: 2,148
R
Member
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


Don(resqcapt19)
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