
19TESTING AND FINAL INSPECTION
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Testing and final inspection
Testing
Danger: Disconnect the primary power source.
Do NOT exceed the listed voltages for the
voltage class of equipment under test.
Disconnect shunt connected coils such
as potential transformers.
Do NOT test sensors or relays with high voltage.
Disconnect all sensors and relays before
applying voltage.
With the system erected, assembled and
connected, perform the following 16-step process.
1. Remove all packing and shipping materials.
2. Make sure that all internal parts are clean
and dry. If moisture is present, blow dry
with warm air.
3. Remove any shipping blocks from relays.
4. Check for damaged insulation by applying
potential tests to the primary bus. Conduct
potential tests phase-to-phase and phase to
ground in accordance with “field test” values
as shown in table 1.
—
Table 1: 60 Hz, RMS, withstand voltages
(1 minute)
Rated
maximum
voltage (kV rms)
Factory test
(kV rms)
Field test
(kV rms)
DC field
test* (kV)
none
* The column headed “DC field test” is a reference for those using
DC tests to verify the integrity of connected switchgear. It represents
values believed to be appropriate and approximately equivalent to
the corresponding power frequency withstand test values specified
for each voltage class of switchgear. The presence of this column in
no way implies any requirements for a DC withstand test on AC
equipment. Also, it does not imply that a DC withstand test is an
conformance tests. When making DC tests, raise the voltage to the
5. With the main circuit de-energized and
grounded, check the continuity of all circuits
after installing the circuit breakers. Energize
the control source and operate the equipment.
Indicating instruments verify the continuity
of current transformer circuits and energizing
of the main circuit.
Control circuit checkout
Danger: The breaker or cutout device
of the local control power circuit
must remain open when using a
separate control power source.
1. The preferred method to check the control
circuit is to furnish a separate temporary source
of control power of the required control voltage
rating. The temporary source must have a
properly coordinated backup protective device
in the circuit. Set the device to clear any faults
that might occur. Initially, all circuit breakers
should be in the DISCONNECT position and the
main circuit de-energized and grounded. When
AC control power is supplied from control power
transformers in the switchgear, remove all fuses
in the transformer circuits.
2. Rack and place all circuit breakers in the
DISCONNECT position.
3. Open all normal control power source
disconnects, if supplied.
4. Check each control switch or pushbutton.
Make sure that it is in the OPEN position.
5. Connect a temporary control power source to
the circuit load terminals in the switchgear.
Energize the control circuit from the temporary
control power source. Refer to the project-
specific electrical drawings for connections.
6. Place one circuit breaker into the TEST position.
When the on-off switch is in the ON position,
the charging of the closing springs of an
electrically operated circuit breaker indicates
connection to the control power.