ABB REJ 527, Operator'S Manual, Page: 28 / 36

28
1MRS 751055-MUM Directional or Non-Directional Earth-Fault Relay
Operator’s Manual
REJ 527
When the test circuit has been completed and the switchgroups set, the auxiliary
voltage may be connected to the relay. The operation of the test circuit can be
verified with the aid of a multimeter.
5.2.1. Testing of the matching transformers
Test each used 0.2 A or 1 A current transformer input separately. Apply a pure
sinusoidal voltage to the relay and compare the current value indicated on the
display of the relay with that shown by the ammeter. The measurements can be
made, for instance, at the rated current of the relay. Note that the relay shows the
measured current as a percentage of the rated current I
n
of the energizing input used.
Test the 100 V voltage transformer input. Apply a pure sinusoidal voltage to the
relay and compare the voltage value indicated on the display of the relay with that
shown by the voltmeter. The measurements can be made, for instance, at the rated
voltage of the relay. Note that the relay shows the measured voltage as a percentage
of the rated voltage U
n
of the energizing input used. Note that the rated voltage is
user-selectable 100 V, 110 V, 115 V or 120 V.
Test the phase angle measurement. Apply a pure sinusoidal voltage and current with
a known phase difference. The measurements can be made, for instance, at the rated
voltage and at 100% and 5% of the rated current of the relay.
5.2.2. Testing of the zero-sequence voltage stage U
0b
>
Before the test is started:
1. Record the actual SGR settings for later restoring.
2. Set the relay switchgroups as follows:
Setting values can be those actual used.
Starting
Close switch S1 and slowly increase the test voltage until the relay starts and the
indicator U
0
is lit. Then read the start voltage value from the voltmeter.
Operate time
1. Set the test voltage at 2 x the setting value of stage U
0b
>.
2. Switch off S1 and clear indicators and reset output relays. The clock is started
by closing switch S1 and stopped by closing output contact PO1.
When the relay starts, the START indicator on the front panel is lit with yellow light.
When the relay operates, the red indicator turns on.
5.2.3. Testing of the non-directional earth-fault current stages
Before the test is started:
1. Record the actual SG_ settings for later restoring.
2. Set the relay switchgroups as follows:
SGR1 = 4 U
0b
> to SO1
SGR2 = 1 t
b
> to PO1
SGR1 = 4 I
0
> to SO1