TB MRU3-2 12.00 E
25
6.4
Secondary injection test
6.4.1
Test equipment
•
Voltmeter with class 1 or better
•
Auxiliary power supply with the voltage correspond-
ing to the rated data on the type plate
•
Three-phase voltage supply unit with frequency regu-
lation (Voltage: adjustable from 0 to
≥
2 x U
N
)
•
Timer to measure the operating time (Accuracy class
±
10 ms)
•
Switching device
•
Test leads and tools
6.4.1
Example of the test circuit
For testing of the
MRU3-2
relay, a three phase volt-
age source is required. Figure 6.1 shows an example
of a three-phase test circuit energizing the
MRU3-2
re-
lay during test. The three phase voltages are applied
to the relay in Y-connection.
Figure 6.1: 3-phase test circuit
