I shoulda clarified. This controller is actually an old numeric controller with mechanical relays.
What Currently said about radios made me think. This controller is in a box suspended by an arm which connects to the main electrical cabinet. All the comnnections go thru this arm. The operator has a bid a** radio sitting on top of this arm. He doesnt have a mike or anything like that connected, but could that be a problem?
As far as seperate power supplies, The inputs have the same power source as the controller (an external power supply) the power going to the power supply however is shared with the rest of the controls and this includes the power going to the NO/NC relays on the controller.
spkjpr, yes the coils have suppressors installed. they were factory installed because previously they had that very problem you described.
The controller had been replaced only to have the same problem reoccur 3 weeks later. The most recent incident was during an electrical storm when the power went off for a breif moment.
Siemans has a 24vdc UPS that would fit in nicely with the power supply. However I was hoping to nail down the problem before I throw to much money at it.
