Disconnecting Means

[Jeremy T.]

I have to connect a band saw in a machine shop. The old one has a disconnect mounted to it. The new one has its own round switch that has a lockable cover. Does it need a seperate handle type disconnect. The engineer seems to think the disconnect has to be a handle type that can be thrown quickly in case of emergency.
Any thoughts?

 

[iwire]

Code wise the disconnect switch is not required for emergency shutdown the disconnect is required for maintenance and service.


That said the engineer can exceed code and if they want a typical disconnect switch so be it.

 

[Jeremy T.]

Ahh! Finally a common sense answer. Thanks

 

[Jraef]

As a general rule, those cheap little rotary thru-door disconnect switches are only UL-508 listed, meaning they can only be used as a local disconnect, i.e. for LO/TO near the motor. They are not listed to be used as a switch in a Branch Over Current Protective Device (meaning even if fused), therefore are REQUIRED to have either a UL-98 listed (knife switch type) fused disconnect or a UL-489 listed circuit breaker ahead of them as the Branch OCPD. So if you have a CB in a panel that feeds ONLY this one machine, that works. If it's a feeder that feeds other loads, it doesn't. In that case, a UL-98 listed fused disconnect on the wall next to it is probably the best option. If you aren't sure and want to cover your bases, just go that route, there's no harm in over doing it a little.

 

[infinity]

Would a saw of this type used in a machine shop require a stop/start setup to that it cannot restart on it's own if there were an interruption in power.