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#194004 - 05/04/10 04:21 PM Demand factors for refrigerators in a laboratory
Bravo Offline
Member
Registered: 05/04/10
Posts: 30
Loc: NY, USA
Can I apply table 220.56 - demand factors for kitchen equip to laboratory refrigerators? The refrigerators are intermittent in use similiar to kitchen ref's.

thanks in advance.
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#194006 - 05/04/10 05:03 PM Re: Demand factors for refrigerators in a laboratory [Re: Bravo]
gfretwell Online   content


Member
Registered: 07/20/04
Posts: 9039
Loc: Estero,Fl,usa
I vote no. Refrigerators are basically motors.
I see this being 220.14(C) referencing 430.24

(125% of the biggest motor plus 100% of the rest).

If you are coming back from a power failure every one of those reefers will be presenting LRA at the same time. Depending on where you are, that can be a fairly frequent thing.

I am open to being wrong tho. wink

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#194024 - 05/05/10 07:12 AM Re: Demand factors for refrigerators in a laboratory [Re: gfretwell]
George Little Offline
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Registered: 01/18/04
Posts: 1488
Loc: Michigan USA
I'm going to agree with Greg on this one for the reason he mentioned plus if we are talking about refrigeration type equipment there is nothing in Article 440 that I am aware of that allows us to apply a demand factor.
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George Little
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#194032 - 05/05/10 11:45 AM Re: Demand factors for refrigerators in a laboratory [Re: George Little]
HotLine1 Offline


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Registered: 04/03/02
Posts: 6776
Loc: Brick, NJ USA
Agree with Greg and George!
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John
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#194035 - 05/05/10 01:24 PM Re: Demand factors for refrigerators in a laboratory [Re: HotLine1]
ghost307 Offline
Member
Registered: 05/09/05
Posts: 899
Loc: Chicago Illinois USA
Greg bring up an excellent point. After a power failure, that refrigerator will be running as a continuous load until it gets its contents cooled down. Some of that laboratory refrigerators that I've done go down to way below -100 degrees.
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Ghost307
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#194049 - 05/06/10 09:28 AM Re: Demand factors for refrigerators in a laboratory [Re: ghost307]
Bravo Offline
Member
Registered: 05/04/10
Posts: 30
Loc: NY, USA
thanks guys. I will size 125% of the biggest motor plus 100% of the remainders.
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