Part
12470
Rev. 2 3/25/99
14
14.
When overload relay trips, timer stops and output is de-energized. Current reading is
retained on ammeter. Timer indicates elapsed time in seconds or cycles.
15.
Turn test set OFF with POWER ON/OFF Switch.
16.
Record results.
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).
