commercial kitchen exhaust fan

[hhsting]

I have, 120V, single phase, 1 HP commercial kitchen exhaust fan ACCUREX Model: XRUD-141-VG.

The circuit breaker size provided is 20A. Designer says manufacturer does not provide MOCP for exhaust fan and one can use NEC 2014 Section 430 to size the breaker. I always thought for commercial kitchen exhaust manufacturer does provide MOCP. Can one use NEC 2014 section 430 to size circuit breaker for commercial kitchen exhaust fan?

 

[infinity]

What is the FLA in the table in article 430? Multiply that by 250% for the maximum OCPD.

 

[LarryFine]

Are you concerned a 20a breaker is too large or too small?

I've wired many kitchen hoods, and 20a worked perfectly.

 

[hhsting]

Are you concerned a 20a breaker is too large or too small?

I've wired many kitchen hoods, and 20a worked perfectly.

Too large

 

[texie]

Too large

Well, if you think a 20 amp breaker is to large for this motor, your not gonna like the answer of what size it could be.

 

[LarryFine]

Too large

It won't be. 2.5 x 8 = 20. Your motor will use more than 8a on 120v.

 

[texie]

It won't be. 2.5 x 8 = 20. Your motor will use more than 8a on 120v.

The OP is indicating 120 volt. 40 amp.

 

[LarryFine]

The OP is indicating 120 volt. 40 amp.

Yep. NEC says 16a full-load current. 2.5 x 16 = 40a allowed.

As long as it reliably starts on a 20a breaker, you're golden.

 

[infinity]

Yes definitely not "too large".

 

[Fred B]

Yep. NEC says 16a full-load current. 2.5 x 16 = 40a allowed.

As long as it reliably starts on a 20a breaker, you're golden.

Also if mfg is not providing name plate requirements of motor, you I believe are forced to size not only circuit protection to hp of motor but also wiring. While you can size motor protection to as small as will be tolerated (doesn't trip under load) but the wiring I dont think you would have that option to undersize, unless you want to change wire too (if wire sized to that of protection) and it trips the undersized breaker.

 

[texie]

Also if mfg is not providing name plate requirements of motor, you I believe are forced to size not only circuit protection to hp of motor but also wiring. While you can size motor protection to as small as will be tolerated (doesn't trip under load) but the wiring I dont think you would have that option to undersize, unless you want to change wire too (if wire sized to that of protection) and it trips the undersized breaker.

This motor can be wired with #12 and a 40 amp breaker.