13.2
SEL-311C Relay Instruction Manual Date Code 20060320
Testing and Troubleshooting
Testing Philosophy
Testing Philosophy
Protective relay testing may be divided into three categories:
➤ acceptance
➤ commissioning
➤ maintenance
The categories are differentiated by when they take place in the life cycle of
the relay as well as by the test complexity.
The paragraphs below describe when to perform each type of test, the goals of
testing at that time, and the relay functions that you need to test at each point.
This information is intended as a guideline for testing SEL relays.
Acceptance Testing
1. When:
a. When qualifying a relay model to be used on the utility
system.
2. Goals:
a. Ensure that the relay meets published critical
performance specifications such as operating speed and
element accuracy.
b. Ensure that the relay meets the requirements of the
intended application.
c. Gain familiarity with relay settings and capabilities.
3. What to test:
a. All protection elements and logic functions critical to
the intended application.
SEL performs detailed acceptance testing on all new relay models and
versions. We are certain the relays we ship meet their published specifications.
It is important for you to perform acceptance testing on a relay if you are
unfamiliar with its operating theory, protection scheme logic, or settings. This
helps ensure the accuracy and correctness of the relay settings when you issue
them.
Commissioning
Testing
1. When:
a. When installing a new protection system.
2. Goals:
a. Ensure that all system ac and dc connections are
correct.
b. Ensure that the relay functions as intended using your
settings.
c. Ensure that all auxiliary equipment operates as
intended.
3. What to test:
a. All connected or monitored inputs and outputs, polarity
and phase rotation of ac connections, simple check of
protection elements.
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