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#194004 - 05/04/10 07:21 PM Demand factors for refrigerators in a laboratory  
Bravo  Offline
Member
Joined: May 2010
Posts: 30
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 08:03 PM Re: Demand factors for refrigerators in a laboratory [Re: Bravo]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,120
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



Greg Fretwell

#194024 - 05/05/10 10:12 AM Re: Demand factors for refrigerators in a laboratory [Re: gfretwell]  
George Little  Offline
Member
Joined: Jan 2004
Posts: 1,489
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.


George Little

#194032 - 05/05/10 02:45 PM Re: Demand factors for refrigerators in a laboratory [Re: George Little]  
HotLine1  Offline


Member
Joined: Apr 2002
Posts: 6,868
Brick, NJ USA
Agree with Greg and George!


John

#194035 - 05/05/10 04:24 PM Re: Demand factors for refrigerators in a laboratory [Re: HotLine1]  
ghost307  Offline
Member
Joined: May 2005
Posts: 915
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.


Ghost307

#194049 - 05/06/10 12:28 PM Re: Demand factors for refrigerators in a laboratory [Re: ghost307]  
Bravo  Offline
Member
Joined: May 2010
Posts: 30
NY, USA
thanks guys. I will size 125% of the biggest motor plus 100% of the remainders.



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