Manual MRI3 GB
Woodward
DOK-TD-MRI3 Rev.A
47
6.4 Secondary injection test
6.4.1 Test
equipment
Voltmeter, Ammeter with class 1 or better,
auxiliary power supply with the voltage corresponding to the rated data on the type plate,
single-phase current supply unit (adjustable from
0
to
≥
4 x In),
single-phase voltage supply unit (adjustable from 0 to
≥
1.2 x Un)
(Only for relays with directional feature),
timer to measure the operating time
(Accuracy
class
≤
±10 ms),
switching device and
test leads and tools.
6.4.2 Example of test circuit for MRI3 relays without directional feature
For testing MRI3 relays without directional feature, only current input signals are required. Figure
6.1 shows a simple example of a single phase test circuit with adjustable current energizing the
MRI3 relay under test.
Figure 6.1: Test circuit