a water source heat pump with MOCP of 15A - fused disconnect size

[SeniorElectricalEngineer]

Greetings,

We have a water heat source pump with MOCP of 15A. Would it be acceptable to specify a 30A fused disconnect switch with a 15A fuse in it in the circuit powering up this pump? My biggest concern is someone potentially installing a 30A fuse in the 30A fused disconnect switch by mistake making the installation non-NEC compliant. Any thoughts?

 

[retirede]

What you propose is compliant.
It’s almost impossible to account for a future idiot.

 

[infinity]

As retired stated don't worry about future idiots. The NEC doesn't care about them so neither should you.

 

[Dennis Alwon]

Greetings,

We have a water heat source pump with MOCP of 15A. Would it be acceptable to specify a 30A fused disconnect switch with a 15A fuse in it in the circuit powering up this pump? My biggest concern is someone potentially installing a 30A fuse in the 30A fused disconnect switch by mistake making the installation non-NEC compliant. Any thoughts?

You can use a non-fused disconnect if the heat pump doesn't state "Max Fuse Only" or something to that nature

 

[suemarkp]

Is there a reason the source branch circuit breaker cannot be 15A?

 

[don_resqcapt19]

Greetings,

We have a water heat source pump with MOCP of 15A. Would it be acceptable to specify a 30A fused disconnect switch with a 15A fuse in it in the circuit powering up this pump? My biggest concern is someone potentially installing a 30A fuse in the 30A fused disconnect switch by mistake making the installation non-NEC compliant. Any thoughts?

There is no way around that with fuses...fuses 30 amps or less have the same physical size so the a fused disconnect that you are going to be using a 15 amp fuse in will always have a 30 amp rating.