4
It is recommended that the protective device actually be operated where possible for best assurance.
The ideal functional test is to actually change input quantities (e.g., instrument transformer secondary
injection) to the protective device to thoroughly test the entire protection path. However, it may be necessary to
simulate contact operation with a "jumper" when device activation is not possible.
injection) to the protective device to thoroughly test the entire protection path. However, it may be necessary to
simulate contact operation with a "jumper" when device activation is not possible.
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Protective circuit functional testing is accomplished as follows:
·
Conduct a Job Hazard Analysis.
·
Verify that testing will not disrupt normal operation or endanger staff or
equipment.
equipment.
·
With lockout relays reset, initiate lockout relay trip with the protective device
contact.
contact.
4
·
Verify the lockout relay actually tripped from the protective relay action.
Verify that circuit breakers actually tripped (or other protective action
occurred) from the lockout relay action.
Verify that circuit breakers actually tripped (or other protective action
occurred) from the lockout relay action.
·
Activate the lockout relay from each protective device. After the first full test
of lockout relay and breakers, it may be desirable to lift the trip bus from the
lockout relay so as not to repeatedly trigger the lockout--a meter may be
substituted.
of lockout relay and breakers, it may be desirable to lift the trip bus from the
lockout relay so as not to repeatedly trigger the lockout--a meter may be
substituted.
Caution: Do not forget to reconnect the trip bus to
the lockout relay when testing is complete.
the lockout relay when testing is complete.
Where functional testing of ALL protection circuits is unfeasible, testing of the most
critical protection circuits and devices is still recommended.
critical protection circuits and devices is still recommended.
Reclamation standard design for lockout relay and circuit breaker control circuits
includes the use of the red position/coil status indicator light to monitor the continuity
of the circuit through the trip coil. These lights should be lit when the lockout relay is
in the "Reset" position or when the breaker is closed. If the light is not lit, this may
indicate a problem with the coil integrity which should be addressed immediately.
includes the use of the red position/coil status indicator light to monitor the continuity
of the circuit through the trip coil. These lights should be lit when the lockout relay is
in the "Reset" position or when the breaker is closed. If the light is not lit, this may
indicate a problem with the coil integrity which should be addressed immediately.