motor breather with fused diconnect

[mjmike]

If a motor has a local fused disconnect switch, does it matter that the upstream breaker and circuit ampacity is oversized? An existing installation has a breaker and circuit sized feeding a duplex motor control panel sized for 2 motors operating at 1 time. The control panel and motors will be demoed and replaced with a single small motor with integral starter. Will add a local fused disconnect with proper fusing for 1 motor but now the feeder and upstream breaker are way oversized.

 

[Strathead]

If a motor has a local fused disconnect switch, does it matter that the upstream breaker and circuit ampacity is oversized? An existing installation has a breaker and circuit sized feeding a duplex motor control panel sized for 2 motors operating at 1 time. The control panel and motors will be demoed and replaced with a single small motor with integral starter. Will add a local fused disconnect with proper fusing for 1 motor but now the feeder and upstream breaker are way oversized.

Doesn't matter, in fact, many electricians fail to realize that the motor branch circuit with a fused disconnect start at the disconnect, but a motor branch circuit with a non fused disconnect starts at the feeding breaker. Article 430 conductor sizing is for the branch circuit only.

 

[mjmike]

Doesn't matter, in fact, many electricians fail to realize that the motor branch circuit with a fused disconnect start at the disconnect, but a motor branch circuit with a non fused disconnect starts at the feeding breaker. Article 430 conductor sizing is for the branch circuit only.

Thanks, that was how we were interpreting it as well. Wanted to do a double check.