Installation and Operating Instructions - Crompton Instruments

Testing Relay 1
Now you are ready to test the relay
contact function. This example assumes
a nominal 120V product.
With no measuring signal input, the relay
should be tripped (no Voltage ). Confirm
that Relay 1 contact is de-energised.
Apply a three-phase, variable, AC voltage
source to the input, initially set to 120V.
Now decrease the voltage slowly.
Confirm Relay 1 contact is energised.
Note that the SPR is checking each phase
for a voltage less than 100 V.
Once the voltage falls below 100 V, the
relay will trip, and the status display will
indicate as shown opposite.
The # symbol indicates that Relay 1 has
tripped (and is still tripped).
Confirm that Relay 1 contact is now deenergised.
Now increase the voltage until the # sign
disappears. This should be a level of 103
V (which is the trip setting of 100 V plus
the differential of 3 V)
The relay will change state, back to
energised.
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