Secondary Injection Testing - ABB SPAJ 131 C User Manual And Technical Description

Secondary
injection testing
18
Testing, both primary and secondary, should
always be performed in accordance with na-
tional regulations and instructions.
The protection relay incorporates an IRF func-
tion that continuously monitors the internal
condition of the relay and produces an alarm
signal on detection of a fault. According to the
manufacturer's recommendations the relay
should be submitted to secondary injection test-
ing at five years' intervals. These tests should
include the entire protection chain from the
instrument transformers to the circuit breakers.
The secondary testing described in this manual
is based on the relay's setting values in the
concerned application. If necessary, the second-
ary testing can be extended by testing the pro-
tection stages throughout their setting ranges.
As switch positions and setting values may have
to be altered during the test the correct positions
of switches and the setting values of the relay
during normal operation conditions have to be
recorded, for instance, on the reference card
accompanying the relay.
To enable secondary injection testing the relay
has to be disconnected, either through dis-
connectable terminal blocks or a test plug fitted
on the relay.
DANGER!
Do not open the secondary circuit of a cur-
rent transformer during testing, if the pri-
mary circuit is live. The high voltage pro-
duced by an open CT secondary circuit could
be lethal and may damage measuring instru-
ments and insulation.
When the auxiliary voltage is connected to the
protection relay, the relay performs a self-testing
program. The self-testing does not include the
matching transformers and the contacts of the
output relays. The operational condition of the
relay is tested by means of ordinary relay test
equipment and such a test also includes the
matching transformers, the output relays and
the accuracy of the operate values.
Equipment required for testing:
- adjustable voltage transformer 0...260 V, 1 A
- current transformer
- ammeter, accuracy ±0.5%
- stop watch or counter for time measurement
- dc voltage source for auxiliary supply
- switches and indicator lamps
- supply and pilot wires
- calibrated multimeter
The secondary current of the current trans-
former is to be selected on the basis of the rated
current, 1 A or 5 A, of the relay energizing input
to be tested. The energizing inputs are specified
under the heading "Technical data, Energizing
inputs".