Part
12470
Rev. 2 3/25/99
19
IMPORTANT
Refer to manufacturer's instructions for instantaneous trip time. If increasing test current does not
decrease tripping time, current at which minimum tripping time was first observed is the
instantaneous trip current value. Additionally, the test method outlined above is sometimes referred
to as the "jogging" or "step" method. For nearly all applications, this method works best; however,
there is another method referred to as the "run-up" method. Instead of the OUTPUT MODE Switch
being in the MOMENTARY position, it is placed in the MAINTAIN position and the ammeter is
placed in the NORMAL position. When the output is initiated, rotate OUTPUT CONTROL knob
clockwise and observe current reading on ammeter. When the device trips, record trip current. If
this method is used, it should be noted that the device is being heated with continuous current, and it
is hard on the variable auto transformer windings and brush(es) (can cause premature wear-down of
the brush(es) and carbon buildup - see SERVICE DATA).
GROUND FAULT ELEMENT
1.
Set-up CB-832 with:
a.
POWER ON/OFF Switch in OFF position. (instrument displays OFF)
b.
OUTPUT CONTROL knob at minimum,
`0'
position.
c.
OUTPUT MODE Switch in center OFF position.
2.
Connect one end of a high-current lead to one pole of ground fault circuit breaker.
Connect other end of this lead to the COMMON terminal of test set.
3.
Connect one end of second high-current lead to the other side of the same pole of the
ground fault circuit breaker. Connect the other end of this lead to the appropriate
output terminal (see SELECTION OF OUTPUT TERMINAL).
4.
Connect test set to suitable single-phase power supply.
5.
Turn test set on with POWER ON/OFF Switch (instrument displays should light).
6.
Use RANGE Switch to select ammeter range so test current will be near full scale
and no less than 10% of full scale.
7.
Put ammeter DISPLAY MODE in MEMORY position.
8.
Place timer STOP MODE Switch in CURRENT position.
9.
Select desired timer display mode and range.
10.
Rotate OUTPUT CONTROL knob clockwise and momentarily press OUTPUT
