Auxiliary Relay Test

Auxiliary relay test

This test aimed to test relay’s output contact, pick-up and drop off voltage, operating and resetting time.

Required equipment for Auxiliary Relay Test

  • Sverker (used as Voltage source and used its voltmeter).
  • Multi-meter [used as Ammeter]
  • Miniature Circuit Breaker 2Pole (MCB).

Mechanical check and visual inspection:

  • Check tightness for all wires.
  • Check ferrules.
  • Check for physical damage or defect.

Test connection

I. Check output contact:

Our Auxiliary relay has several points, 2 used for Coil, before injecting any voltage on Auxiliary relay’s Coil, check contacts at its normal condition which mean Normally Open (NO) contact is being opened and Normally Closed (NC) contact is being closed, Inject the desired control voltage of Aux. coil (which is normally 125 volt DC), at which Aux. relay will pick up that’s mean its contact will change its position i.e NO contact will be closed and NC contact will be opened.

II. Pick-up and drop off current and voltage:

Pick up voltage can be measured using voltmeter when the coil voltage is increased gradually from O volt, the Aux. relay will operate (i.e Contacts change its normal status No will be closed and vice versa) at a certain voltage. This voltage is called pick-up voltage, Record the reading of voltmeter and Ammeter which is pick-up voltage and current.

Drop-off voltage can be measured using voltmeter when the coil voltage on an operate relay is decreased gradually, the relay will release (i.e its contact will return to its normal status) at a certain voltage. This voltage is called drop-off voltage, Record the reading of Ammeter which is drop-off current.

Ill. Operating and resetting time:

Adjust voltage source at the coil operation voltage of Aux. relay (in our case 125 v DC), To get operating time, adjust sverker at (on+time location) and switched MCB ON, To get resetting time, readjust voltage source at 125 volt DC and switch MCB OFF.

IV. Burden test:

  • Adjust voltage source (sverker) at 125 volt DC, select on position and make MCB ON.
  • Record reading of Ammeter.
  • Calculate burden by multiplying coil operated voltage and reading of Ammeter.

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