Figure. 5.2.2 - 72. Relay behavior when nominal voltage injected.
The image collection below presents the relay's behavior when voltage is injected into the relay via
secondary test equipment during an earth fault. The measurement mode is 3LN+U4 which means that
the relay is measuring line-to-neutral voltages. The VT scaling has been set to 20 000 : 100 V. The U4
channel measures the zero sequence voltage which has the same ratio (20 000 : 100 V).
Figure. 5.2.2 - 73. Relay behavior when voltage injected during an earth fault.
Troubleshooting
When the measured voltage values differ from the expected voltage values, the following table offers
possible solutions for the problems.
Problem
Check / Resolution
The measured
voltage amplitude in all
phases does not match
the injected voltage.
The scaling settings or the voltage measurement mode may be wrong, check that the settings
match with the connected voltage transformer (
Measurement
→
Transformers
→
VT Module).
The measured
voltage amplitude does
not match one of the
measured phases./
The calculated U0 is
measured even though it
should not.
Check the wiring connections between the injection device or the VTs and the relay.
A
AQ
Q-C215
-C215
Instruction manual
Version: 2.07
72
© Arcteq Relays Ltd
IM00040