Need Help!- fadal vmc 15 axis amplifiers buzzing

[dougputt]

Hi everyone

I just moved up from Boss 5 with Mach to a Fadal VMC15. Really like the machine but on startup or when a axis trips I get a really bad buzzing from the three relays in the top r/h of the rear cabinet. If I jog and reset the axis it goes away. But the noise is obviously not something that should be happening. Also I switched the taps and jumpers for the voltage from 440V to 210V at the transformer. I can't find any other changes that need to be done in the manual but am I missing something?

Doug

[carbidecraters]

We had this same problem it was a couple of small relays that jarrred loose after moving. They look like ice cubes! You can start the machine with the door openand find the relays that are clicking away and then power down and remove and reinstall them. Sometimes they only need a push.

[Al_The_Man]

I would confirm the voltage present on the coils when picked up, AC inductive devices do not tolerate much in the way of under voltage.
Al.

[Neal]

Since you made a major change in the applied voltage I would recommend redoing the Servo Loop Gain.

Neal

[dougputt]

Ok, looks like it's just the top relay thats buzzing away. When I push on it slighlty (with a piece of wood) it stops buzzing. Or of course when I reset the axis it stops.

Doug

[dougputt]

thanks for the replies,

Neal, where would I find the Servo loop gain adjustment procedure in the maintenance manual?

Regards
Doug

[Al_The_Man]

Originally Posted by dougputt When I push on it slighlty (with a piece of wood) it stops buzzing. Doug

This is usually an indication the contactor armature is not seating properly or low coil voltage.
Al.

[dougputt]

Thanks Al, I will check the voltages.

[dougputt]

I'm just trying to find the voltages and the amplifier setup in the manuals.

[dougputt]

Anyone have any information on setting servo loop gains as Neal mentioned?

DP

[dougputt]

Servo loop gain adjusted and no joy, relay is still buzzing like a .....

[Neal]

IT may b that the motor is causing the relay to buzz. Try touching up the COMP pot on the amplifier and see if you can sttle it down.

Neal