Servo motor overtemp alarms never have a good ending if the problem isn't resolved. You'll see component breakdown not far behind. I think of servo motor overtemp alarms as a wakeup call that you are about to experience a failure.

Re: What is an Overspeed Alarm?

Overspeed alarams can be caused by a few different things.

• bad wiring: check your cabling leading to the resolver/encoder on your motor system. This includes possible loose pins and bad connections at the termination points.
• bad shielding: Your cables should be shielded internally and properly grounded at one end only; which should be at the drive or control cabinet. Motor systems with a resolver are sensitive to noise and the overspeed alarm can result from common noise.
• bad resolver alignment: If the resolver coupling has come loose for any reason or if your resolver has changed position in relation to the servo motor it will throw out an overspeed alarm.
• resolver wiring: If you have replaced any components in your servo motor system including the resolver, motor, drive, or cabling, it could be connected wrong. The resolver wires can be wired in reverse which could change the location of the zero position. Mis-wiring can definitely cause overspeed alarms also.

These are just some suggestions, but they should encompass most of the reasons behind overspeed alarms.

Air Valve Noise Suppression

Add noise suppressor in parallel to your air valve to reduce or eliminate the unwanted noise. Then you can move forward and continue troubleshooting from there if the problem still persists.

Re: Ross Air Valves

Experiment with cheap air valves from ebay. Spec it out and replace with something else. I'll bet your problems stem from a harsh environment and not the Ross air valves themselves.

Cheap Cube Relays

I agree with the ebay thing... You can get cheap cube relays there all the time. In this case, you can get brand name relays at a fraction of the price of going to your relay distributor.

Automation Direct Industrial Circuit Breakers

This post makes me wonder how many companies how many made in USA circuit breakers are still out there. So many industrial parts are imported, it's hard to say if a circuit breaker from the Dominican Republic would be much different than one from Mexico or China.

Troubleshooting a tach generator for an electric motor

I've seen tach generator end bearings go bad. It isn't an electrical issue but it becomes noisy for a time before it stops working. The bad tach bearings will lead to an electrical failure at some point.

Also, in my experience as an electrician in an industrial plant, the noisy tach generator bearings are not always easy to hear, so most of the time you will find the bearings gone bad after it's too late.