Electrical Test Instruments MAC-20 User Manual

Electrical
Test lnstruments
MAC-20
Retrofit
package
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relocation
according to
steps 20
through 25 in
general procedures
outlined above.
Pick-Up
of lnstantaneous
Element
1.
Consult manufacturer's
literature
to determine
any necessary
precautions
and
expected test results.
Check the breaker's
instantaneous
setting.
Pickup should
occur at about
that current.
2.
Follow steps
1 through 18
in
general
test
procedures,
as required,
to set up
the
breaker
test set.
3. Setup MAC-20
for
C.L. MOM.
4.
Set MAC-20
RANGE
to lowest range
that is
greater
than
desired test
current.
5.
Set TIMEBASE
to CYCLES.
6. Fress
PRESET
key. Adjust
preset
time
to 6.0 cycles.
(This
value
may be
set higher
or lower,
depending
on how fast the
breaker trips).
7. Press PRESET
again
to
return
to normal
mode.
8. Select
MEMORY mode.
L Repeatedly
jog
the INITIATE
button,
white adjusting
the OUTPUT
CONTROL
higher,
until the
circuit breaker
trips instanta
neously. This is
the approximate
pickup
point.
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 con-
tinue.
\*
'10.
Close breaker under
test.
11.
By repeating
the test, determine
the MINIMUM
SETTING of
the OUTPUT
CONTROL
,
at which
the breaker
under test opens immediately,
whenever
the
INITIATE
button is depressed.
12. Read and
record ammeter
reading as instantaneous
pick-up
of the
breaker.
13. Repeat
the above
test for the other
poles
of the circuit
breaker.
14.
Shut down
test set, disconnect
breaker, and
prepare
for
subsequent
testing or
relocation according
to steps 20
through 25 in
general
procedures
outlined above.
lnstantaneous
Trip Time
Test
1. Perform lnstantaneous Pickup
Test as outlined
above.
2. Adjust controls to
obtain currenl above
pickup,
at
approximate
desired multiple
of
rating.
3. Close breaker
under test.
4. Press the INITIATE
button. Breaker should
trip instantaneously.
5. Read and record
timer and ammeter readings
as instantaneous
trip time and
Electrical Test lnstruments. lnc.
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Electrical Test Instruments MAC-20 Specifications

General

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