Re: [CAD_CAM_EDM_DRO] Re: G201 death/repair/questions/problems (long post)

> 1) That one's got me stumped because I've heard of that happening a
> few times before.

I'm going to start at the motors since they seem to be the likely cause
at this point.

> About a year ago I set up a relay that turned the power supply on and
> off every second on a running drive. I left it on over the weekend
> where it cycled 200,000 times. No problems were experienced.
>
> Where this will happen is if you switch the DC power to the drives.
>
> That is a no-no and the damage occurs on turning the power off. The
> inductive energy stored in the motor windings has nowhere to go so it
> generates a damaging voltage whose harm only shows up the next time
> you turn the drives on. The drives didn't blow when you turned the
> power on; they were killed when the power was turned off the last
> time.

I switch the power supply at the AC mains in. It takes a second for the
LEDs on the G201s to go out. I have noticed that they do flash a bit
brighter and then fade out when mains power is switched off.

> 2) You can't hurt the drives by cranking the motor while the drives
> are off. The motor acts as a generator that simply begins to power
> the drives. You can't crank it fast enough (>500 RPM) to hurt them
> unless you are Superman.

That would be tough, and while I'm pretty tough, I'm not that tough :-).

Chris