Raptor
54
Test:
Select and inject the desired current. The chronometer will start up. When the circuit
breaker trips, it will stop, indicating the trip time. If you wish to test another point of the
curve, repeat the process at another current value.
Overcurrent relay
This test, also very frequent, consists of injecting a fault
current through the primary of the CT and verifying the
correct operation of the associated protection in secondary
of this CT and the effective trip of the MV/HV circuit
breaker, which must control this. It is a very good way of
verifying that the Primary/Secondary/Primary chain works
perfectly.
The primary of the CT must be injected with currents above
the nominal current to simulate a fault current. In this case,
it is especially important for the impedance of the
connection between the equipment and the CT to be as low
as possible. This is achieved with adequate cable sizes, correct geometric layout of the
cable in its path, in order to reduce the turn area that is created to a minimum, and
above all, to keep the shortest possible distance to the CT. In many cases it is highly
recommendable to move the Raptor equipment close to the CT, using the people
elevator buckets.
Although the relay trip time is verified, the primary aim of this test is not to verify it as
such, which is assumed to be tested in secondary, but to verify the aforementioned chain.
Template configuration:
The template is configured as followed:
• Generator: Pass-through turn
• Time display: As chronometer in seconds
• Chronometer start-up: ON output
• Chronometer stop: By dry contact N.O.
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