Electrical Test Instruments PI-6000
Section IV - Operating Instructions
==============================================================================
==============================================================================
Copyright(C) 1994-2019 Electrical Test Instruments, LLC All Rights Reserved
Page IV-3
SINGLE POLE MOLDED CASE CIRCUIT BREAKERS
Timing Test
1.
Consult breaker manufacturer's literature to determine any necessary
precautions and expected test results. A test current of three times the
rating of the breaker should be used for this test.
2.
Follow steps 1 through 16 in pre-test installation and setup, as required, to
set up the breaker test set.
3.
Setup MAC-21 for C.L. Maint (MAINTAIN on).
4.
Set MAC-21 RANGE to lowest range that is greater than desired test
current.
5.
Set TIMEBASE to CYCLES.
6.
Press PRESET key. Adjust preset time to 5.0 cycles. This value may be set
higher or lower, depending on trip characteristics of breaker.
7.
Press PRESET again to return to normal mode.
8.
Select MEMORY mode.
9.
Repeatedly jog the INITIATE button, while adjusting the OUTPUT
CONTROL higher, until the desired test current is read on the ammeter. If
insufficient current is obtained at maximum position of the rheostat, set
the OUTPUT TAP control to the next higher tap, return the rheostat to zero,
and continue.
10.
Press RESET button.
11.
Set TIMEBASE to SECONDS.
12.
Select MAINTAIN mode.
13.
Press and release INITIATE key; OUTPUT ON light should glow, timer
should run, and current display should read desired output current.
14.
While test is running, observe current reading. If necessary, adjust to
correct value by using rheostat control, or press MAINTAIN key for current
hold.
15.
When breaker trips, the test set output should de-energize, timer should
stop, and OUTPUT ON light should turn off.
16.
Read and record trip current and trip time. Compare to manufacturer's
time/current curve.
17.
If test is to be repeated, make sure that breaker cools completely.
