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To clear the displays the output voltage control is returned to reset.
NOTE:
a)
In the burn mode the trip circuit is inoperable and the
tester will continue to drive current into a fault. The
fault current is limited to a nominal 5mA and the output
voltage will decrease with increase in current.
b)
In the breakdown mode if excessive current is drawn by
the "DUT" the desired output voltage may not be
achieved. The specification for the "DUT" would then
have to be checked to decide on the validity of the test.
The leakage current is not displayed in this mode.
c)
It is advisable to return the output voltage control to
reset before switching off the tester.
d)
During applied voltage tests the current which flows
into and across the surface of the "DUT" is the leakage
current and is the resultant of two components:-resistive
and reactive. Resistive current is that which flows as a
result of losses in the insulation of the "DUT". Reactive
current is that which flows as a result of capacitance in
the "DUT" and will increase with increase in
capacitance. It must be taken into account when
carrying out an applied AC voltage test.
e)
If the voltage select switch is operated when the voltage
control is not at the "Reset" position, the HV circuit
will de-energise and it will be necessary to return the
voltage control to "Reset" to reactivate the HV circuit.
-8-
2.2.3
MODE SELECT
Three modes of operation are selectable.
Breakdown:-
The tester will trip should breakdown occur in the
"DUT" (high frequency leakage currents).
This position switches in a level detector whose input is
Trip:-
variable over the range 0 to 3mA. The tester will trip if
the leakage current in the"DUT" exceeds the level that
is set. The tester will also trip for breakdown.
The tester will not trip in this mode regardless of
Burn:-
breakdown or leakage currents but the 'burn' current is
limited to a nominal 5mA.
2.2.4 TRIP LEVEL
This control sets the level on the trip detector that must be exceeded
before a failure of the "DUT" is indicated.
2.2.5 POWER INLET
This multi-function item combines an IEC inlet with a double pole
switch, fuse drawer and 115/230 volt mains power selector.
2.2.6 INDICATORS
A red lamp which indicates that the high voltage output
kV ON:-
circuit is energised.
Fail:-
A red lamp which indicates that the "DUT" has failed
and the trip has triggered. A buzzer sounds in unison
with the fail lamp to give an audible indication that the
"DUT" has failed.
2.2.7 DISPLAYS
Output Voltage kV:- The voltage applied to the "DUT" is displayed and
the value at failure is held until the tester is reset.
Leakage Current mA:- Leakage current through the "DUT" is displayed
and the value at failure is held until the tester is reset.
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