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Panel feeder size for panel with multiple freezers on it

mshields

Silver Member
Joined
Aug 9, 2011
Messages
105
Location
Plymouth, MA
I've got an optional standby panel with something like 16 -80 freezers on it (they happen to be 208V-sinlge phase and approximately 2kVA each). I generally, in keeping with Article 440.22, take these at 100% of their nameplate rating. I have a couple of questions.

1) Am I correct that there is no allowance in the code for applying a diversity factor. Realistically, the compressors cycle on and off and I know that when you put a meter on such panelboards, the actual demand load is consistently below 40% of the connected load.

2) If the code provides no relief here, as a practical matter, I'd be interested in the groups experience with regard to the actual demand load seen from such a panel.

Much appreciated,

Mike
 
mshields said:
something like 16 -80 freezers on it
Typo there Mike?

See 430.26 via 220.50, as the EE you may be able to swing this.

On the off chance that there are 16-80 compressors in a commercial kitchen see 220.56.
 
Chris, There are quantity 16, minus 80 freezers on a single panelboard and this is in a lab. Whether you understood that or not, clearly 430.26 is particularly useful. Thankyou! Did some more research and found that these particular freezers had a 25/25 duy cycle. 25 minutes "on"/25 minutes "off" with the door closed. It seems to me taking into consideration that it might not be a perfect 50/50 split at any given time and that doors are occaisionally opened, a 70% demand factor seems reasonable. Would you agree?

Thanks alot Chris!
 
Bear in mind, unless you have some kind of delayed start, they will all hit the service at once after a power failure.

This is not like a bunch of ranges, it is an unattended load and they will all hit at once if they get above -80.

It might actually take a while to get them out of sync again.
 
An excellent point! Although these are all generator backed and if they're down more than a matter of seconds, they've got bigger trouble.
 
mshields said:
Chris, There are quantity 16, minus 80 freezers
Gotcha, Revco's?

Mike you can post the degree symbol in a post by holding down the Alt key and hitting 0176 on the right hand keypad. Your post will read;

"16 -80°F freezers".
 
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