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Joined: May 2010
Posts: 30
B
Bravo Offline OP
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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.

2017 / 2014 NEC & Related Books and Study Guides
Joined: Jul 2004
Posts: 9,673
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G
Member
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
Joined: Jan 2004
Posts: 1,507
G
Member
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
Joined: Apr 2002
Posts: 7,283
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Agree with Greg and George!


John
Joined: May 2005
Posts: 984
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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
Joined: May 2010
Posts: 30
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Bravo Offline OP
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thanks guys. I will size 125% of the biggest motor plus 100% of the remainders.


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