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Discussion Starter · #1 · (Edited)
Hi guys, my girlfriend was having problems with her pool pump, (which ended up not being an electrical problem) but while i was looking at it something jumped out at me. And btw i'm in Canada.

The pump is wired with #14 AWG on a 20A breaker.

Nameplate reads:
3/4 HP
230/115V
8/16A

It's wired with 120v and when i look through the CEC i come up with #12 AWG on a 40A breaker when wired at 120v.

I just want to make sure this is right before i go buy the parts.

Also, the CEC lists a 3/4 HP motor at less than 16A. i don't have it in front of me but i think it was 13.6A.......i assume its safer to use the specs straight from the nameplate instead of the CEC?

Thanks guys.

Edit: It's also controlled by a switch rated at 15A. should this be changed as well?
 

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Master Electrician
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In the USA 8 amps @ 240 volts, 16 amps @ 120 volts. Equipment labeled with both the horsepower and the amperage is allowed to use the nameplate amperage for circuit sizing. You do not need to use motor calculations to size the circuit.
 

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Lic Electrical Inspector
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1,843 Posts
In the USA 8 amps @ 240 volts, 16 amps @ 120 volts. Equipment labeled with both the horsepower and the amperage is allowed to use the nameplate amperage for circuit sizing. You do not need to use motor calculations to size the circuit.
What code section?
 

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Lic Electrical Inspector
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Hi guys, my girlfriend was having problems with her pool pump, (which ended up not being an electrical problem) but while i was looking at it something jumped out at me. And btw i'm in Canada.

The pump is wired with #14 AWG on a 20A breaker.

Nameplate reads:
3/4 HP
230/115V
8/16A

It's wired with 120v and when i look through the CEC i come up with #12 AWG on a 40A breaker when wired at 120v.

I just want to make sure this is right before i go buy the parts.

Also, the CEC lists a 3/4 HP motor at less than 16A. i don't have it in front of me but i think it was 13.6A.......i assume its safer to use the specs straight from the nameplate instead of the CEC?

Thanks guys.

Edit: It's also controlled by a switch rated at 15A. should this be changed as well?
Here in the US the 2008 NEC allows #14 for up to 40A on a motor, but the EGC has to be #12 for a pool filter motor. The NEC also requires the use of article 430 for sizing motor bc conductors, OCPD's, and disconnects. Not the nameplate info. Can't help you with the CEC.
 

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Idiot Emeritus
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What code section?
A slight paraphrase of 430.6 (A) (1) says to use the currents listed in the tables (430.247 - 250) to size the conductors, not the nameplate current.

If the motor nameplate current is higher than the table value, then you use the nameplate value.

Like the 50HP 460V 3ø motor I connected last week; usually the nameplate current of such a motor would be around 60 amps. The table calls for 65 amps. The nameplate current of this motor was 99 amps. It was 12 pole (595RPM).

So I pulled #1 THHN copper to it.
 

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Lic Electrical Inspector
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A slight paraphrase of 430.6 (A) (1) says to use the currents listed in the tables (430.247 - 250) to size the conductors, not the nameplate current.

If the motor nameplate current is higher than the table value, then you use the nameplate value.

Like the 50HP 460V 3ø motor I connected last week; usually the nameplate current of such a motor would be around 60 amps. The table calls for 65 amps. The nameplate current of this motor was 99 amps. It was 12 pole (595RPM).

So I pulled #1 THHN copper to it.
This is because the motor is built for low speed.
 

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Here in the US the 2008 NEC allows #14 for up to 40A on a motor, but the EGC has to be #12 for a pool filter motor. The NEC also requires the use of article 430 for sizing motor bc conductors, OCPD's, and disconnects. Not the nameplate info. Can't help you with the CEC.
#14 for 40 amps I like my toast golden, not burnt
 

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Lic Electrical Inspector
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And you know this how??
This was in reference to Microminds post.

12 poles. 595 rpm's. 430.6(A)(1) states;

Motors built for low speeds (less than
1200 RPM) or high torques may have higher full-load currents,
and multispeed motors will have full-load current
varying with speed, in which case the nameplate current
ratings shall be used.

So if the motor is less than 1200 rpm's or high torque the nameplate current ratings shall be used instead of the tables.

 

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I've already cited it several times. NEC 2008 430.6 (A)(1) Exception No. 3. You do not use Table Values for ALL motor loads.
True; if, and only if, the nameplate is attached to the appliance, not the motor.

If the nameplate is attached to the motor itself, you use the higher of the table values or the nameplate.
 

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Lic Electrical Inspector
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1,843 Posts
brric said:
I've already cited it several times. NEC 2008 430.6 (A)(1) Exception No. 3. You do not use Table Values for ALL motor loads.
Pool filter motors are not motor-operated appliances and therefore, exception 3 does not apply. Pool filter motors are covered under UL Standard 1081 found here. My original post is compliant.
 
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