What is a 32 relay?
32 Directional power relay A relay that operates on a predetermined value of power flow in a given direction or upon reverse power flow, such as that resulting from the motoring of a generator upon loss of its prime mover.
What is a 33 relay?
33 – Position Switch. 34 – Master Sequence Device. 35 – Brush-Operating or Slip-ring Short Circuiting Device. 36 – Polarity or Polarizing Voltage Device. 37 – Undercurrent or Underpower Relay.
What is a 59 relay?
59 – Overvoltage Relay 60 – Voltage or Current Balance Relay. 62 – Time-Delay Stopping or Opening Relay.
What is a 47 relay?
47 Phase Sequence or Phase Balance Voltage Relay Provides protection for rotating equipment from the damaging effects of excessive negative sequence voltage resulting from phase failure, phase unbalance and reversed phase sequence.
What is a 42 relay?
The high voltage relay RL 42 can switch voltages up to 6,000 V AC in combination with high currents. In addition, it is often still necessary to switch very small voltages in the mV-range and currents in the mA-range. The requirements regarding quality of switching contacts are consequently extremely high.
What is a 67 relay?
Abstract: Directional overcurrent relaying (67) refers to relaying that can use the phase relationship of voltage and current to determine direction to a fault.
What is a 94 relay?
Tripping or trip-free relay is a relay that functions to trip a circuit breaker, contactor, or equipment to permit immediate tripping by other devices, or to prevent immediate reclosing of a circuit interrupter if it should open automatically.
What is a 50 relay?
Calibration of an instantaneous overcurrent (50) relay consists simply of verifying that the unit “picks up” within a reasonably short amount of time if ever the current magnitude exceeds the prescribed pickup value.