Maintenance
98 REVISION 02 * MAINTENANCE SIMOSEC * 832-6063.0
24.3 Cable testing
For cable testing, the operating and installation instructions of SIMOSEC switchgear
must be observed as well as the specifications and recommendations of the cable and
cable termination manufacturers.
Voltage transformers or surge arresters connected to the circuit to be tested must be
removed or disconnected.
SIMOSEC switchgear is designed for rated voltages up to 27.6 kV and the connected
cable can be tested with a DC test voltage of up to 72 kV for cable tests. During this
test, the main bus bar voltage can be energized at normal system AC voltage up to
27.6 kV.
Do not exceed test voltage recommended by the cable manufacturer.
Preconditions for testing: • Three-position switch in "OPEN" position
Procedure to be followed
for cable testing:
Ö Isolate the panel feeder to be tested.
Ö Isolate all sources of voltage from the cable circuit to be tested, and lockout
switching devices to prevent re-energization.
Ö Verify safe isolation from sources of voltage.
Ö Ground the cable to be tested.
Ö OPEN compartment cover (see “Removing the cable compartment cover” on
page 92).
Ö Connect source of test voltage to the cable connection point of cable to be tested.
Ö Switch switching devices of panel to be tested to test position (OPEN position).
Ö Test cable in accordance with instructions of the test equipment manufacturer.
Ö Do not exceed test voltage recommended by the cable manufacturer.
Ö After test is complete, ground the cable that was tested.
Ö Remove test connections from the cable connection point.
Ö Reinstall the cable compartment cover.
The cable has been tested. Other panels can be tested, or the panel can be put into
operation again.
Rated voltage of
switchgear
DC test voltage,
maximum value
VLF* test voltage
cosine-rectangular wave-
form rms (peak) voltage
VLF* test voltage
sinusoidal waveform rms
(peak) voltage
15 kV 55 kV 22 (22) kV 16 (22) kV
27.6 kV 72 kV 33 (33) kV 23 (33) kV
* Very Low Frequency. Refer to IEEE Std. 400.2-2004, ’’IEEE Guide for Field Testing of Shielded Power Cable
Systems Using Very Low Frequency (VLF).“ For cosine-rectangular waveform, the rms value is taken as equal to the
peak value. For sinusoidal waveform, the rms value is 0.707 times the peak value if distortion is less than 5%.