Electrical Test Instruments MAC-20 User Manual

Electrical
Test lnstruments
MAC-20
Retrofit Package
Section ll -
Detailed Description
MAJOR
PARTS IDENTIFICATION
AND OPERATION
MAC-20 Control
Panel
TIME DISPLAY:
This 4
digit LED
display normally
indicates
the elapsed
time of a
current
pulse.
ln
SECONDS
mode, it
displays time
up to 9.999
seconds,
then auto-
ranges
to 99.99 seconds,
999.9
seconds,
and 9999 seconds.
ln CyCLES
mode, it
reads time
(based
on 60 Hz),
up to 999.9
cycles,
then autoranges
to 9999
cycles. lf
time
exceeds
maximum
display capacity
(10,000
seconds
or 10,000
cycles), the
display
will read "OVER".
ln PRESET
mode,
the
display indicates
the maximum
time
of
initiation (oN
time), in
either cycles
or seconds. A reading
of zero disables
the
pRESET
function,
and allows
any time.
CURRENT
DISPLAY:
This 4
digit LED
display indicates
the output
current. ln
CONTINUOUS mode,
as well
as
in
MEMORY
mode
before and during
a test, the
display indicates
true-RMS
output
current in real
time, After
completion
of a test, in
MEMORY mode,
the
display shows
the true-RMS value
as computed
over
the entire
length
of the
pulse.
This
mode is indicated
by a flashing
LED
on the MEMORY
key.
lf a
reading
exceeds
the maximum value
for the
selected range, the
display will
read
"ovER".
INITIATE
key: This key
is used to turn
ON the
output of the test
set.
The
LED in
the key
indicates that
the MAC-20 is
attempting
to turn the
output ON, but
other conditions
(such
as interlocks)
could keep
the output from
actually
turning on. ln MOMENTARy
mode, the key
must be held
to keep output
current on; if LATCH
is
enabled, the
output
will stay
on until the breaker
trips, or the
STOP or RESET
button are
pressed.
The
MAC-20
must
be RESET in order
to
initiate
output,
and in N.C.
or N.O. contact
modes,
the contact status
(continuity)
must indicate
that
the breaker is
closed. lf the
output on
time exceeded the PRESET
time, as indicated
by flashing
of the PRESET
key LED,
the
INITIATE key
will automatically
reset the MAC-20
and turn
the output on.
STOP key: This
key is used to
turn the output of
the test set OFF. lts
LED indicates
that output is not
being turned
on by the MAC-20, but
other conditions
could cause
output voltage to
be ON. Use of this key
is usually necessary
only when
the LATCH is
enabied, and it is necessary
to abort the
test before the breaker
trips. NOTE: lt is
important
to realize
that the
interlock
system
of the circuit breaker
test set may
also turn
the output
off, but it will turn back
ON
when
the interlock
condition is
cleared.
RESET key: This key resets
the displays on
the MAC-20, and
arms the
pulse
reading
system. The LED on
the
key
indicates that the
system is reset and
armed. In version
1.4
and
later, RESEI
a/so takes the unit
out of
PRESET
ADJUST
mode, and
turns
LATCH off.
PRINT
key
combination: On models equipped with
a
printer
option,
the STOP and
RESET keys may be
pressed
simultaneously
to send the time
and current readings in
Electrical
Test lnstruments,
lnc.
Page ll-4
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All Rights Reserved

Electrical Test Instruments MAC-20 Specifications

General

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