M-0359 Syncrocloser® Check Plus Relay

Please Note: As of 12/31/2022, Beckwith Electric will no longer be manufacturing the M-0359 Syncrocloser® Check Plus Relay.

  • Beckwith will accept orders for these products until 8/31/2022 and all products ordered must ship before 12/31/2022.
  • Please contact us to request a quote and place orders.
  • This product may have an alternative replacement product, M-7651A, depending on your application needs. Please contact us for details.


The M-0359 Syncrocloser® Check Plus Relay is used as a permissive relay for secure reclosing of a circuit breaker by verifying that voltage and phase angle conditions are within pre-set limits before allowing the breaker to close. The M-0359 uses phase angle/slip frequency to verify synchronism to provide rapid restoration with the smallest possible angle settings without a time delay. Analog outputs of phase angle, bus voltage, line voltage, DV and DF are provided for SCADA system interface.
Enhances system stability when applied to transmission and primary distribution reclosing schemes.

  • Detects a static phase angle across an open breaker in 0.5 sec. to assure a fast permissive for reclosure.
  • Simultaneously measures voltage magnitudes to ensure that they are within upper, lower, and difference limits.
  • Includes dead line/dead bus closing features.
  • Remote command widens the phase angle setpoint to respond to system emergencies or to narrow the setpoint of the two systems are isolated to close the breaker very close to 0°.
  • Transducer analog outputs are SCADA compatible.