COMBITEST - Relay test system

COMBITEST relay test system provides a wide range of testing capabilities. All parts of the COMBIFLEX relay and the overall system can be accessed for testing. COMBITEST also means additional personnel safety during testing.

In a test it is possible to inject signals to the isolated relay in order to observe its performance and operation limits. Problems may thus be discovered before an actual protection operation is called for. A safety feature in COMBITEST is that CT shorting is automatic upon insertion of the test handle into the test switch. No external shorting links are needed on the test handle. Trip circuits are interrupted prior to CT shorting during insertion of the test handle.

The secondary injection test facility can also be used to enable the relay system to receive a simulated or recorded power system event in “play-back” mode. This permits testing of cases, which may have caused confusion or concern in relay operation or lack of operation. Numerical play-back can also be further facilitated using test system simulation software.

• Fail-safe sequence disconnecting trip circuits when the test-plug handle is inserted.
• Latching feature so that when the test-plug handle is withdrawn the relay stabilises in its reset position before the trip circuits are restored.
• Complete isolation of secondary instrument transformer circuits.
• Trip-block plug, which isolates a trip circuit without interrupting other circuits, allows the trip output to be monitored, and also provides visual indication of an isolated trip circuit.
• Block-plug handle, which disconnects all circuits, routed through the test switch.
• Ammeter test-plug with local automatic shorting device in case of inadvertent opening of a CT circuit.
• Auxiliary station power supply made available for operating test equipment.
• Extension bases which facilitate measurement and adjustment of plug-in module circuits.