Problem- Power in reverse

[ben_heinman]

I have a Habor spindle chiller unit for a CNC machine that keeps getting a reverse power alarm. The chiller had been working for years without any problem when one day noticed it wasn't running and had an alarm on the display. Even though I knew that no one had reversed the power I switched two phases to make sure and still got the alarm. I know it is somewhere on the board because I took a board out of another identical unit, plugged everything in the same and it worked. I am thinking that it may be one of the capacitors that is causing the problem. Is there a way that I can measure the capacitors with a meter to tell if it is defective? Does anyone have any other ideas what could cause this reverse power problem?

[vger]

Look up "ESR Meter" for checking caps. ESR is Equivilant Series Resistance and it uses an AC signal across the cap to check it. They are pricy to buy outright but you will probably find a DIY circuit and info somewhere on the web.

Steve