Can anyone tell me the amperage requirement on this?

[JMWElectric]

Hey guys,

I have a 3 phase air compressor and i cannot tell what the amperage requirements are.

Can you?

 

[JMWElectric]

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[jumper]

Hey guys,

I have a 3 phase air compressor and i cannot tell what the amperage requirements are.

Can you?

What info is listed on the nameplate?

Or what is the make and model?

 

[dkidd]

It depends on the voltage.

 

[jumper]

What voltage are you supplying?

 

[electricguy61]

FLA is "full load amps"

 

[jumper]

FLA is "full load amps"

Yeah, but ya gotta use the NEC tables for conductor sizing. If installing separate overloads you use that.

 

[electricguy61]

Yeah, but ya gotta use the NEC tables for conductor sizing. If installing separate overloads you use that.

#12 THHN on a 20amp breaker, with overload protection. Not too difficult on small motors.

I agree when the motor gets larger you would need further research.

 

[Jraef]

Assuming where your confusion lies (you didn't make that clear.)

1. The motor is dual voltage, so you connect it differently for low and high voltages
   
2. The Low voltage connection is designed to accept either 208V or 230V, because they know that it is common to be given either one, and if they only list 230V they get inundated with phone calls from people asking if it's OK to use it on 208V. So they just go ahead and put it on the nameplate. Technically, the motor is likely designed slightly differently that a single voltage version in that it probably has a little more iron, but that's just between them and their conscience.
   
3. So the current ratings (FLA) are listed in the same order as the voltage ratings.
   
4. At 208V the FLA = 13.8; At 230V the FLA = 13.2; At 460V the FLA = 6.6

 

[Jraef]

Yeah, but ya gotta use the NEC tables for conductor sizing. If installing separate overloads you use that.

True, but it's the answer to a question not asked... We don't know WHY he was confused about the amperage.

 

[JMWElectric]

What voltage are you supplying?

Supplying 230v

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[Ingenieur]

What voltage?

 

[Ingenieur]

For sizing
Ckt 15.2
ol's 13.2

 

[jumper]

For sizing
Ckt 15.2
ol's 13.2

Does not the motor say PF~ .8 and would need to be multiplied by 1.25?

Note to T430.250

For 90 and 80 percent power factor, the figures shall be multiplied by 1.1 and 1.25, respectively.

 

[Ingenieur]

Does not the motor say PF~ .8 and would need to be multiplied by 1.25?

Note to T430.250

For 90 and 80 percent power factor, the figures shall be multiplied by 1.1 and 1.25, respectively.

Doesn't that apply only to synchronous motors ?

 

[jumper]

Doesn't that apply only to synchronous motors ?

Yep. Good catch. Thanks.:thumbsup:

 

[Ingenieur]

Yep. Good catch. Thanks.:thumbsup:

even a broken clock is right twice a day :happyyes:

 

[jumper]

So #14 THHN and up to a 30A would work, no?

 

[jumper]

even a broken clock is right twice a day :happyyes:

Well at least once depending on the clock.

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