Design Ideas

I have a grinder that we are going to put new controls on. The blade motor is 480 and the hydraulic motor that opens the blade chamber is 120 volts.

The motor starter for the blade motor needs to have power isolated from it before the hydraulic opening circuit will work.

This is will all be from the same panel and one main 480 disconnect and a 480 x 120 transformer.

I could but a breaker before the motor starter for the blade motor but that would mean opening the cabinet to isolate it which I would like to avoid.

blade motor is 40 hp. Fitting dual safety contactors above the blade motor starter would chew up all the panel space at that size.

Any ideas?

VFD, clutch on motor (energize to engage).

Use normally close contacts from the blade starter breaking the feed to the hydraulic open circuit. Use a limit switch breaking the control power the blade starter if the door is open. Allowing the start if closed.

How about a cable operated disconnect to your blade motor circuit breaker. You could lock it out without opening cabinet. We use these on our regrinders for plastic, lock out the grinder and still able to use the actuator to open up for cleaning and blade changes. Once the unit is opened we then lock out the control side also.

I had a simular problem, differant equipment. I bought some 6 pole disconect switches.
600V rated we were using 480 v 3 ph. worked very well.