Polarity checking of voltage transformers should be performed to
confirm that the wiring circuitry between the voltage transformers and
the relay is correct, which is a prerequisite for the protection functions
in the relay to operate correctly. The circuit breaker tripping circuit,
interlocking and signaling wiring should also be tested.
When commissioning the relay, secondary testing is performed. If wanted,
secondary testing can also be used for more elaborate testing of the relay
’
s
functionality.
Relay commissioning contains:
1. Verifying that the correct application-specific settings have been entered into the
relay. This is done by reading the relay settings either via the HMI or serial
communication and comparing these to the calculated application-specific
settings. If read via serial communication, the settings can be stored as a
commissioning setting record file.
2. Verifying the voltage measurements
–
refer to Section 5.3. Measurements
verification
3. Testing of signal routing to output contacts
–
refer to Section 5.4. Function test
4. Testing of digital input signals availability
–
refer to Section 5.5. Digital input
test
5. Testing of overvoltage protection
–
refer to Section 5.6.1. Testing overvoltage
protection
6. Testing of residual voltage protection
–
refer to Section 5.6.2. Testing residual
voltage protection
5.2.
Maintenance instructions
Relay preventive maintenance includes verification of the relay operation and
changing the possibly worn parts. The verification is carried out to ensure that the
relay hardware operates correctly, that is, as it did when first commissioned.
When performing periodic preventive maintenance, the whole circuit breaker
tripping circuit should also be tested, if possible. This can easily be done with the
plug-in unit removed from the relay case, as the terminals for output contacts in the
relay case are left open in such a situation.
When the plug-in unit is removed from the case, internals of the case
must not be touched. Relay case internals may have high voltage
potential and touching these may cause personal injury.
5.2.1.
Relay verification
The relay maintenance verification contains:
50
REU 610
REU 610
Voltage Protection Relay
Operator's Manual
1MRS755770
