DM 5 lathe VFD

[dougputt]

Hi

I am converting a DM5 mini-lathe to Mach3 with C11 BOB (cnc4pc)

I'm just messing around with the VFD at this point trying to figure out how to wire in the Field sense wire as the VFD will go to stall condition after 15 sec's. Somehow I need to feedback into the Rapier Cube 505 VFD so it will not shut down.

Any ideas?

[Al_The_Man]

It threw me when you mentioned VFD? The 505 is a DC inverter control is it not?
Are you getting an error because you have no field connected?
If the motor has no wound field , you could provide field current with a resistor.
Al.

[dougputt]

Hi Al

Yes I guess it would be called non-isolated motor speed controller for DC permanent magnet motor. Or at least thats what the spec's say.

Yes you are correct I do not have the field connected, that's were I'm stumped the old system only had input to the positive field connection at the dc controller and I can't verify where this signal is coming from. It is not coming directly from the motor.

Regards
Doug

[Al_The_Man]

I am not really familiar with that drive, but many of these inverter drives offer output for a wound field which a P.M. motor does not have, usually you just leave the field disconnected for a PM motor, but if the drive expects to see field current, you may have to provide it if there is no option to jumper detection out.
The reason being that a wound field motor that loses field current when running can run away uncontrollable rpm, this is why field loss detection was built in to some.
It almost looks in the manual that field loss detection is optional for non-PM motors, but I don't see anyway to turn it off?
Al.