Pool pump motor OCP

[Captorofsin1]

Hello. Since the new requirement for pool pump motors of having to upgrade to GFCI protection when a pool pump motor is replaced, I've had a handful of these calls to upgrade the OCP.

I fully understand the GFCI requirement.

When looking at the 230 volts max amps it would read that the max amps would be 9.5 amps.

15 (amps) x .80 = 12 (amps).
This means that 9.5 amps is well under the 80% max nominal load. This means that a 15 amp OCPD device would be good in this application.

Every motor that I've encountered so far has (as per the specification sticker and electrical code) not required over a 15 amp double pole OCPD. Why does everyone that I encounter have a 20 amp OCPD?

Am I missing something?

 

[augie47]

Likely the pump has overload protection so your overcurrent (GFSC) protection can be selected for 430.52 which would allow for 2.5 X the Table FLA.

The 20 amp would be more suited to address start-up current.

 

[Captorofsin1]

The one I'm referring to now is a US motors ASB 2983

 

[Captorofsin1]

Likely the pump has overload protection so your overcurrent (GFSC) protection can be selected for 430.52 which would allow for 2.5 X the Table FLA.

The 20 amp would be more suited to address start-up current.

The one I'm referring to now is a US motors ASB 2983. It's a two speed. High speed max current is 9.2 amps. I never considered startup current. I just saw where I read 9.2 amps and went from there.

 

[Jraef]

The one I'm referring to now is a US motors ASB 2983. It's a two speed. High speed max current is 9.2 amps. I never considered startup current. I just saw where I read 9.2 amps and went from there.

Motor circuits are a special case. If you size the breaker too closely, you can suffer nuisance tripping. That’s why the NEC rules in 430 are different from other rules elsewhere.

 

[Captorofsin1]

Motor circuits are a special case. If you size the breaker too closely, you can suffer nuisance tripping. That’s why the NEC rules in 430 are different from other rules elsewhere.

I wouldn't think that a 15 amp breaker with nuisance trip for a motor that has a max current of 9.2 amps. That means The startup current would have to be over 6 amps. That seems like a lot.

Based on what I'm seeing lately because of this new code, a lot of these newer pump motors are more efficient. I mean a 1.5 HP motor 230 volts drawing a max of 5.7 amps on each leg.

 

[Jraef]

Starting current is generally considered to be 600% of the motor FLA. so 55A. Some brands of breakers have the mag trips set at the factory at 400%, so no a 15A breaker might trip at 60A, but there is a large +- range around those values.

 

[Captorofsin1]

Likely the pump has overload protection so your overcurrent (GFSC) protection can be selected for 430.52 which would allow for 2.5 X the Table FLA.

The 20 amp would be more suited to address start-up current.

Up to 250% of max current?