Flow Ctrl Tech Engineering

Inductive Flyback & Relay Contact Arcing: Sizing RC Snubbers, Flyback Diodes & MOVs

Prevent electrical contact destruction and PLC resets: suppressing back-EMF voltage spikes generated by de-energizing solenoid valves, contactor coils, and mechanical motor brakes.

  • De-energizing an unsuppressed 24V DC solenoid coil can generate an inverse voltage spike exceeding 1,000 volts.
  • High-voltage back-EMF arcs across open relay contacts, degrading contacts and resetting nearby microprocessors.
  • For DC coils, wire a 1N4007 diode reverse-biased across the coil; for AC coils, install a series RC snubber.

Flow Ctrl Tech Engineering: Turnkey industrial automation, PLC programming, SCADA development, HMI, fieldbuses, and IIoT architectures. Contact our engineering center at [email protected] or phone +91 91110 91005.