Wire and Breaker size to Chiller

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pault587

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I am trying to order a power panel for a chiller plant. This York chiller has a FLA of 231, 460V 3 phase, and min circuit ampacity of 288. I was planning on using a 300 amp breaker to supply this panel. The panel specs say it is equipped with a 400 amp breaker. Can I still use my 300 amp breaker?
Does anyone see any reason why it should 400?
Then do I size my wire to the 300 amp breaker that will feed the chiller?

Thanks,
Paul
 
"I am trying to order a power panel for a chiller plant. This York chiller has a FLA of 231, 460V 3 phase, and min circuit ampacity of 288. "
The conductor should have an ampacity of 288 amps min.

"I was planning on using a 300 amp breaker to supply this panel. The panel specs say it is equipped with a 400 amp breaker. Can I still use my 300 amp breaker?
Does anyone see any reason why it should 400?"

The 300 amp breaker may trip when the compressor starts.


"Then do I size my wire to the 300 amp breaker that will feed the chiller?"
You size the wire for 288 amps as noted on the unit.
 
pault587 said:
Just to clarify. If I increase the breaker to 400amp that does impact my wire size?

I have been sizing my conductors to the breaker size.
Click to expand...


This type of equipment should have all the information that you need on the nameplate. It should have the MCA or minimum circuit ampacity which is used to size the conductors. Also it should have the maximum OCPD value. If the maximum CB is 400 amps or more then you can use your 400 amp CB with the conductors rated for the MCA.
 
pault587 said:
Just to clarify. If I increase the breaker to 400amp that does impact my wire size?
I have been sizing my conductors to the breaker size.
Click to expand...

The conductor does not have to match the 400 amp breaker. This is an exception for motors/compressors. The conductor is sized at 125% of the FLA
of the motor/compressor. The breaker can be as high as 250% of the FLA per table 430.52. for motors. 440.22 allows 175% for the FLA for compressors
and may be increased to 225% if necessary.
 
Paul587,

Do you need a power panel or would a 400a fusable disconnect be a better

option?

The reason I ask is if you need more circuits than just the chiller,You will

have to add that load to your wire size.

EDIT: after rereading your post,This post makes no sense. 400a c.b. with 300a wire as Bob and Trevor have suggested.
 
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