HC-2
4-1
SECTION 4: BASIC APPROACH TO TESTING
The HC2 is basically a continuously variable high current source, the magnitudes of which are dependent on
the output tap that is selected. Please refer to the Technical Data and
Specifications for the voltage and current ratings of the taps.
The output current is controlled by use of the RAISE CURRENT knob on the control panel. By turning the knob
in the clockwise direction, the current is raised. By turning the knob in the counter-clockwise direction the
output magnitude is decreased.
The RMS value of the output current is displayed on the CURRENTMETER. If the MEM/CONT switch is in the
CONT (for CONTinuous), the meter displays the real-time value of the output. If the MEM/CONT switch is in
the MEM (for MEMory), the highest value of the output current is displayed.
When a breaker is to be tested, the operator may select the SENSE CONTACTS mode or the SENSE
CURRENT mode of operation. If an auxiliary set of non-energized contacts are available, the SENSE
CONTACTS mode may be selected. By pressing JOG or RESET the state of the contacts (be it normally open
or normally closed) are remembered by the unit. The operator may then preset the output current to the
desired level by use of the JOG switch. When this is done, by pressing HC ON (and assuming that the current
level exceeds 10% of the CURRENTMETER range selected), the current will continue flowing after the switch
is released and the TIMER will begin to run.
When the contacts connected to the SENSE INPUTS change state, the TIMER will stop running and the output
current will cease to flow. The TRIP lamp will illuminate as an indication to the operator. If the MEM/CONT
switch is in the MEM mode, the highest output current achieved will be displayed on the CURRENTMETER.
The operator should note this level before the readings begin to decay. Pressing RESET will zero the TIMER
and CURRENTMETER readings, and prepare the unit for operation again.
When the SENSE switch is set to the CURRENT mode, the SENSE INPUTS are not used. This position was
meant mainly for single pole breakers in which the SENSE INPUTS cannot be used. In this mode initiation of
the test is the same as in SENSE CONTACTS mode. The difference is the completion of the test. When the
output current falls below 10% of range (as when the contacts of the breaker open) the TIMER stops running
and the output current turns off. The TRIP lamp illuminates as an indication to the operator.
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