As I mentioned, the MOV (metal oxide varistor) or VDR can be used for suppression, actually they are high resistance at the normal operating voltage and rapidly decrease in resistance as the voltage across them rise, thus offering a load to the voltage surge, on AC some relay manufacturers recommend the R/C method over MOV. Most contactor manuf. supply a tailored R/C suppressor tailored for their devices.
MOV's are more susceptible to destruction than R/C networks and if not discovered, the device no longer has surge suppression.
Al
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CNC, Mechatronics Integration and Machine Design.
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E. |