Medium voltage motors (defined as motors over 1000V) need different protection measures than their lower voltage cousins. Proper motor protection and monitoring in conjunction with a good maintenance schedule will extend the life of your motor and driven application significantly; as well as prevent unscheduled downtime and costly repairs due to easy to prevent failures. Below you will find our three tiers of recommendations for medium voltage motor protection.

Good

  • Multifunction Protective Relay
    • Performs motor waveform analysis, detects ground faults, runs rotor and stator temperature predictive algorithms, measures harmonics, resistance temperature detection, zero sequence, differential options, etc., and is programmable to your specific needs.
  • Short Circuit Protection
    • Fuses or circuit breakers are permissible.
  • Optional: Zero Sequence CT and Resistance Temperature Detection

Better

  • Multifunction Protective Relay
    • Performs motor waveform analysis, detects ground faults, runs rotor and stator temperature predictive algorithms, measures harmonics, resistance temperature detection, zero sequence, differential options, etc., and is programmable to your specific needs.
  • Short Circuit Protection
    • Fuses or circuit breakers are permissible.
  • Resistance Temperature Detection
  • Zero Sequence CT
  • Optional: Differential CTs, Vibration and/or Shock Pulse Monitoring

Best

  • Multifunction Protective Relay
    • Performs motor waveform analysis, detects ground faults, runs rotor and stator temperature predictive algorithms, measures harmonics, resistance temperature detection, zero sequence, differential options, etc., and is programmable to your specific needs.
  • Short Circuit Protection
    • Fuses or circuit breakers are permissible.
  • Zero Sequence CT
  • Resistance Temperature Detection
  • Differential CTs
  • Vibration and Shock Pulse monitoring

If you have any questions about the best types of protection for your specific motor and driven application, give us a call at 800-595-5315, or email us at sales@emcsolutions.com

This article is based off a webinar given by Craig Hartman entitled “Getting the Most out of Your Electric Motor.” You view all of our webinar series here.