Low voltage motors (defined as motors under 1000V) need different protection measures than their higher 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 low voltage motor protection.

Good

  • Electronic Overload Relay            
    • Includes monitoring of overload, loss of phase, phase unbalance, and ground faults.
  • Short Circuit Protection
    • Fuses or circuit breakers are permissible.

Better

  • Programmable Motor Protector
    • Includes programmable monitoring of voltage, amperage, kilowattage, etc. As well as a digital display, digital communications, trip class, recloser protection, and undercurrent monitoring.
  • Short Circuit Protection
    • Fuses or circuit breakers are permissible.
  • Optional: Temperature Monitoring
    • A thermostat or resistance temperature detection method is permissible.

Best

  • Multifunction Protective Relay
    • Includes programmable monitoring of motor waveforms, ground faults, rotor and stator temperature predictive algorithms, harmonic monitoring, resistance temperature detection, zero sequence, differential options, etc.
  • Short Circuit Protection
    • Fuses or circuit breakers are permissible.
  • Resistance Temperature Detection
  • Optional: Zero Sequence CT and Vibration and/or 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”. It is the 1st webinar of a 3-part series. Be sure to check it out!

Got Motor Related Questions? Let Us Get in Touch!