Machine disconnect

[buck33k]

Can a factory installed disconnect on a machine (resistive load only ) be supplied by a feeder with a greater ampacity and OCP than the rating of the disconnect on the machine?

 

[bphgravity]

I doubt it. Equipment cannot be expected to function properly when operated in excess of its rating and listed instructions.

 

[hardworkingstiff]

I doubt it. Equipment cannot be expected to function properly when operated in excess of its rating and listed instructions.

What if it is a fused disconnect?

 

[buck33k]

It is a fused disconnect.

 

[hockeyoligist2]

It is a fused disconnect.

Then it shouldn't be a problem.

 

[buck33k]

Trying to resolve a dispute with co-worker. Fuses are sized for machine. I think this will help.

 

[jim dungar]

The normal premises wiring branch overcurrent protective devices (OCPD)are not intended to protect utilization equipment. Equipment is normally protected by a Supplementary OCPD (see Art 100 definitions).

For those rare conditions where the branch OCPD is intended to protect the equipment, the manufacturer provides sizing requirements (i.e. max fuse or breaker = ???)

 

[petersonra]

Can a factory installed disconnect on a machine (resistive load only ) be supplied by a feeder with a greater ampacity and OCP than the rating of the disconnect on the machine?

How can a machine be a resistive only load? In any case, the power factor of the machine is not relevant to this discussion.

There is no problem with feeding the machine with an over sized feeder. In fact it is fairly common to do this. If one has two machines that each need a 10 A feed, it might be more convenient to run a single 20A feed to both machines.

Each machine still needs its own disconnecting means, and usually has its own OCPD.

Keep in mind the branch circuit OCPD only protects the premises wiring and not the machine in most cases.