Troubleshooting PLC Problem

I have repeated trouble with the input and output cards blowing on my PLC's. I have also experienced CPU Problems like locking up and boards blowing. I also have trouble with power supplies burning out. All of these troubles seem to have started after ComEd updated my electricity in the plant. I would appreciate any suggestions.

Thanksbb

Things to try:

Record your power input, a lot of companies will rent you the equipment. If you explain (complain) to your power supply company they may even come on site and monitor your power for you.
You want to look for spikes and dips and other quality problems.

Add filtering.

Fit more robust cards,
i.e. some 24V cards are sensitive, so use 24-60V DC PLC cards.
or if you are using 115V AC cards, switch to 100 - 260V AC cards.

Complain - be nice about it, but explain what is happening to the power supply company. They will often try to help.

Best wishes,

Doug

I had a similar problem in a IBM plant with many lines running but only my line kept having problems first We started literally smoking and melting Photo eyes about 6 AB eyes damn near caught fire usually a few days but sometimes a few weeks after install. We suspected the photo-eyes so Allen Bradely came out ispected the wiring and then disected the remains of the eyes but then a Micrologix went poof with a power supply. To make a very long and unhappy story short after many plane rides and dealing with a very unhappy customer for at least a month, the problem vanished before we could record the voltage fluctuations. I never understood it!

I agree with Doug. Have your power system checked out. We had a similar problem only we were burning up computer boards.
It ended up being a grounding problem. We redid the grounding system for the buiding and no problems since. Too bad we went through so many computers before we found the cause.

Good Luck!

That sounds like a good guess to me. Bad grounding system, or maybe the Transformer Neutrals aren’t grounded.