T-305E User Manual Version 3.5 | 21
Operational procedure:
vi.
Turn the
MODE
knob to the
PULSE
position.
vii.
Power on the T-305E, the
POWER
indicator lamp will light-up.
viii.
Turn the voltage
ADJUST
knob to the zero position, otherwise the
START
is disabled.
ix.
Press the
START
button. The red
START
button will light up, whilst inside the instrument
the noise of the HV protective device can be heard.
x.
Turn the
ADJUST
knob slowly, and stop it when the voltage rises to the chosen value,
press the
PULSE
button to ascertain whether the voltage is high enough to break-down
the fault point. If the fault does not break-down, raising the voltage further and repeat
the process until the fault breaks down.
x.
The swing of the pointer of the kV meter will indicate the fault status. A small swing
indicates the fault has not broken down; if it is large, the operation is successful.
xi.
Switch the mode switch to CYCLIC and set the required pulse time on the clock by
rotating the dial. The allowable time setting is dependent on the voltage set on the
unit. The capacitor will require a finite time to charge, which will increase depending
on the voltage selected. The minimum times that can be selected for each voltage
level are indicated in the table below.
Note, if lower time settings are selected, the unit will not charge to the full voltage
and may not break down the fault.
Version
Voltage setting
Minimum Time
Setting
1024J
8kV
9s
16kV
7s
32kV
6s
2048J
8kV
18
16kV
12s
32kV
7s
xii.
With the fault being broken down in regular cycles, the user can investigate the cable
path around the pre-location point using the pinpointing equipment. When the time
difference between the acoustic and electromagnetic signals is at a minimum, the
fault has been pinpointed.
xiii.
When the process is completed, discharge the cable and surge generator manually
using the discharge rod (see section 5.1 Using the discharge rod).
