Motor contactor wiring question

[frijoli]

I have 3 servo motors running on 240VAC 1Ø. Spindle and two axis.
Do I need three 2 pole contactors to wire this? It's the only way I can see to break all current paths. Or, could I wire two 3 pole units to accomplish the same thing?
Just trying to make sure I am thinking about this correctly.

Clay

[tblough]

Technically you'd be fine but there is the possibility of one contactor releasing at a slightly different time than the other leaving 115V looking for a return path.

Safest bet is to bite the bullet and put them on separate contactors or wire them in parallel from a single contactor.

[frijoli]

.............snip.............. or wire them in parallel from a single contactor.

How did I miss that? lol

Thanks Tom!

[tblough]

Let me clarify the above. If you are driving three 220VAC motors directly, then you should really be using three individual motor starters with properly sized heaters for overcurrent protection.

If you are supplying 220VAC to three VFDs/Servo drivers, then you can use a single properly sized contactor to control power to the devices. The key here is that the drivers have the overcurrent protection built into them.

[frijoli]

Let me clarify the above. If you are driving three 220VAC motors directly, then you should really be using three individual motor starters with properly sized heaters for overcurrent protection.

If you are supplying 220VAC to three VFDs/Servo drivers, then you can use a single properly sized contactor to control power to the devices. The key here is that the drivers have the overcurrent protection built into them.

I am supplying 3 servo drives. I looked at the wiring diagram they provided and it actually shows them wired in parallel. I'm not sure how I missed that...

Clay