18
COMMISSIONING
1. REQUIRED TEST EQUIPMENTS
•
500V insulation test sets.
•
Variable secondary injection current source rated 10A or greater.
•
Time interval meter
•
Primary injection equipment
•
A DC supply with a nominal voltage within the working range of the relays DC
auxiliary supply ratings
2. INSPECTION
Ensure that all connections are tight and in accordance with the relay wiring diagram and
the scheme diagram. Check if the relay is correctly programmed and the relay is fully
inserted into the case.
3. APPLYING SETTINGS
The relay settings for the particular application should be applied before any secondary
testing is started.
4. PRECAUTIONS
Before testing commences, the equipment should be isolated from the current
transformers and the CTs to be short-circuited, in line with the local site procedures. The
tripping and alarm circuits should also be isolated, where practical. Also, ensure that trip
links are removed.
Ensure that correct DC auxiliary voltage and polarity is applied. See the relevant scheme
diagrams for the relay connections.
5. TESTS
5.1. Insulation
Connect together all relay CT terminals and measure the insulation resistance between
these terminals and all the other relay terminals connected together to earth.
Connect together the terminals of the DC auxiliary supply (only +ve and -ve) and measure
the insulation resistance between these terminals and all other terminals connected
together to earth.
