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

Chris,

Thanks! Here's the top 10 "drive killer" causes in order of
occurrence:

1) Overvoltage.
2) Output shorts (cable, connector, motor).
3) Nothing wrong.
4) Miss-wired / miss-connected motor.
5) Reversed power supply polarity.
6) Test points shorted by probes (G320).
7) No heatsink (when needed).
8) Metal chips inside drive.
9) Component failure (our fault).
10) Blown opto inputs.

(1) and (2) combined constitute 50%, (3) is about 25%. (4) thru (10)
make up about 20%, leaving the remaining 5% for everything else.

Overvoltage edges out everything else and can be very sneaky. Our
drives are rated at 80VDC, all power section parts have a specified
100V breakdown and the drives actually come apart at 108V to 113V. I
know because five out of every 1,000 drives are tested to destruction
for quality control reasons.

On the otherhand, a little NEMA 23 2A motor (Vexta PK268-02) will
happily generate 100V open circuit at 3,000 full steps per second,
330V at 10,000 full steps per second.

It is entirely possible to overvoltage (blow up) a drive with a 24VDC
power supply if there isn't a large (10,000uF) capacitor on the
output of the supply. The capacitor absorbs the voltage.

A sure-fire way of eliminating overvoltage is to place an 82V, 5W
zener diode (1N5375, $0.80/10 at DigiKey) across the drive supply
inputs.

Mariss

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Chris Brick <cbrick@t...>
wrote:

> Mariss,
>
> Thank you so much for the troubleshooting instructions. Your

honesty

> and integrity is second to none. I look forward to doing much more
> business with you in the future.
>
> Now to find the cause of the problems and solve it before blowing

more

> FETS or killing any chance of repair.
>
> Thanks again,
>
> Chris
>