Sizing Service for Freezers

[Eng]

Hello, I have a situation where we have a large amount of -80 208V 1Ph freezers. I have to believe that there is some diversity factor that I can apply to the panels and service that feeds these freezers, but I am unable to find any reference to it in the NEC or on this forum.

Any help is appreciated.

FYI this is phase 2 of an existing project where we installed a 3200A service for the phase 1 freezers and the peak demand of the phase 1 freezers is in the 500A range based on 18months of data.

 

[Barbqranch]

If you have a power outage for long enough, won't they all come on when power is restored, and all run for a while?

 

[Chamuit]

Treat them like multiple A/C's.

 

[jumper]

Treat them like multiple A/C's.

Code reference allowing such?

 

[jumper]

Hello, I have a situation where we have a large amount of -80 208V 1Ph freezers. I have to believe that there is some diversity factor that I can apply to the panels and service that feeds these freezers, but I am unable to find any reference to it in the NEC or on this forum.

Any help is appreciated.

FYI this is phase 2 of an existing project where we installed a 3200A service for the phase 1 freezers and the peak demand of the phase 1 freezers is in the 500A range based on 18months of data.

I would say you cannot find a reference for such, because I do not believe it exists.

 

[electrofelon]

Perhaps the AHJ will let you use 220.87 based on the existing units to size the new infrastructure. It's worth a try.

 

[jumper]

Perhaps the AHJ will let you use 220.87 based on the existing units to size the new infrastructure. It's worth a try.

Good thinking.

 

[ActionDave]

Code reference allowing such?

ARTICLE 440 Air-Conditioning and Refrigerating Equipment

I. General
440.1 Scope
The provisions of this article apply to electric motor-driven
air-conditioning and refrigerating equipment and to the
branch circuits and controllers for such equipment. It pro-
vides for the special considerations necessary for circuits
supplying hermetic refrigerant motor-compressors and for
any air-conditioning or refrigerating equipment that is sup-
plied from a branch circuit that supplies a hermetic refriger-
ant motor-compressor.

Freezer falls into the category of refrigeration equipment, no?

 

[jumper]

Freezer falls into the category of refrigeration equipment, no?

Well I never really thought of it but you are right. Oops.

 

[jumper]

Treat them like multiple A/C's.

Code reference allowing such?

May I some Grey Poupon with my crow?:ashamed1:

You are correct as Action Man pointed out Art. 440 would apply.

 

[iwire]

Freezer falls into the category of refrigeration equipment, no?

OK, so now what?

 

[Eng]

Freezer falls into the category of refrigeration equipment, no?

Correct, but unless I am missing it, I do not see where in 440 it talks about the feeder to panels serving this equipment. There is only mention of the branch circuits serving the equipment. I am trying to reduce the service as a whole.

Any thoughts?

 

[kwired]

Correct, but unless I am missing it, I do not see where in 440 it talks about the feeder to panels serving this equipment. There is only mention of the branch circuits serving the equipment. I am trying to reduce the service as a whole.

Any thoughts?

What the NEC does not address is the reality that the refrigerant compressor is only going to draw what the system demands plus inefficiencies. If a compressor is rated for output of 10,000 BTU then the rated amps will be based on it being loaded to 10,000 BTU. But if system is designed so that only 8000 BTU is the max that will ever be moving then that 10,000 BTU compressor will never see max rated amps unless something changes/fails.

 

[Eng]

What the NEC does not address is the reality that the refrigerant compressor is only going to draw what the system demands plus inefficiencies. If a compressor is rated for output of 10,000 BTU then the rated amps will be based on it being loaded to 10,000 BTU. But if system is designed so that only 8000 BTU is the max that will ever be moving then that 10,000 BTU compressor will never see max rated amps unless something changes/fails.

Basically i need to use the 100% rating, unless the AHJ will allow otherwise. Nothing in the code to allow it.

Thanks