Electrical Test Instruments MAC-20 User Manual

Electrical Test lnstruments MAC-20 Retrofit
Package
Section lll
-
Operating lnstructions
MULTI.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 18 in
general
test
procedures,
as required,
to set up the
breaker
test set.
3. Connect appropriate
output tap to one
pole
of breaker under
test.
4. Setup MAC-20 for
C.L.
MOM.
5. Set MAC-20 RANGE
to
lowest
range that is
greater
than desired test current.
6. Set TIMEBASE to CYCLES.
7. Press PRESET key. Adjust
preset
time to 2.0
cycles.
8. Press PRESET again
to
return
to
normal mode.
9. Select
MEMORY mode.
10.
Repeatedly
jog
the
INITIATE
button, while adjusting the OUTPUT
CONTROL
higher,
until the desired test current is read on the ammeter. lf insufficient
current
is
obtained at maximum
position
of the vernier,
set the OUTPUT
TAP
control to the
next higher tap, return the vernier to zero, and continue.
11. Press
RESET
button.
12. Set TIMEBASE to SECONDS.
13.Select
LATCH mode.
14.lf desired, N.C. mode may be used; connect contacts leads to an unused
pole
of the
breaker.
15. Press and release INITIATE key; CLOSE or OUTPUT ON light should
glow,
timer
should
run,
and current
display should read desired output current.
16.While test is
running,
observe current
reading. lf necessary, adjust to correct value
by using
vernier
control.
17.When breaker trips, the test set output should de-energize, timer should stop,
CLOSE or OUTPUT ON
light should turn off, and TRIP or OUTPUT ON light should
glow
(lf
applicable).
18. Read and
record
trip current
and trip time, Compare to manufacturer's time/current
curve.
19. Repeat
above tests for other
poles
of the breaker. Allow time for breaker to cool.
Note: it is acceptable if all
poles
of the breaker trip within
+l-
15o/o of the manufac-
turer's
time range for the
value of test current chosen. All
poles
of the breaker need
not trip in exactly the same
amount of time.
20. Shut
down test set,
disconnect breaker,
and
prepare
for subsequent testing or
Electrical
Test lnstruments,
lnc
Page
Ill-7
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Electrical Test Instruments MAC-20 Specifications

General

Brand	Electrical Test Instruments
Model	MAC-20
Category	Controller
Language	English