Motor protection

Motors require different protections during startup and normal operation. During startup they must be protected against long acceleration times, locked-rotor conditions, and excessive start attempts - all of which can cause overheating and insulation damage. SYMAP® provides complete protection for both starting and running conditions.

Key motor protection functions include:

  • ANSI 37       undercurrent protection
  • ANSI 51LR   locked rotor protection
  • ANSI 49       thermal overload protection
  • ANSI 50       instantaneous overcurrent protection
  • ANSI 46       phase unbalance / phase loss
  • ANSI 66       start inhibit
  • ANSI 48       incomplete sequence (long start)

Additional features:

  • fully programmable logic for customized interlocks and control sequences
  • up to four nominal value groups (e.g. two-speed motors)
  • optional analog inputs for temperature monitoring

Applicable devices: