Solar CE - Short Test

OPERATING INSTRUCTIONS FOR
"QUICK-CHECK"
SECTION
QUALITATIVE MEASUREMENTS
With
qualitative
checking
it is not necessary to dis-
connect the condenser from the circuit. The condenser
under examination
can be checked In the set under
actual operating conditions with the
set
switched
on,
or with the
set
switched
off. or with the condenser
disconnected
from the circuit if desired, although
this
is not necessary. The Instrument
Is so designed that the
indication
Is definite and instantaneous even though
the
condenser Is shunted by an Inductance
or
resistance.
These factors
do not detract /rom the accuracy
of the
measurements.
The range of
the "Quick-Check" section is from
75
mmf.
to 50 mfd.
To make the instrument
ready for test, the following
procedure should
be followed:
1. Set the selector switch
on the
position
marked
"D".
2. Insert
the special twin conductor
Quick-Check test
leads
Into the tip jacks marked "Condenser
Test".
The red plug should
be connected into the
red
jack and the
black plug into the black
jack.
3. Switch
the meter
to the 5 ma. range.
4. Adjust
the voltage control
so that the
meter reads
5 ma. This
is the null position.
5. Revolve
the capacity dial
to the extreme right
on
"Short" position.
The
instrument
is now ready to
be used in making
tests
on condensers.
The tests
should be
made in the fol-
lowing
order:
1. Test for
opens or intermittently
open
condensers.
2. Test for
shorts or intermittently shorted
conden-
sers.
3. Test for
high R.F. impedance and
high power
factor on electrolytic
condensers.
Now
connect the Quick-Check
leads across the con-
denser under examination.
The black
test
prod
should
be connected
to the point nearest
ground.
NOTE: The test starts when the
test
leads are con-
nected across the condenser. This is very
Important,
as one
must
first watch
for
test Indications at that
moment of contact.
OPEN
TESTS
If there Is no change in the meter reading when the
condenser is connected
across
the
test terminals, then
the condenser
is open. Replace the condenser. Further
checks are not necessary. If the condenser is
not open
the milliammeter
reading will change from 5 ma. to a
lower value.
Open tests can be made even though
the condenser is shunted
by an inductance or resistance.
INTERMITTENT TESTS
If the meter needle flickers;
that is if the milliampere
reading varies
back and forth from
5
mllilamperes
to a
lower value, then the condenser
has an intermittent
con-
nection. Replace
the condenser.
A note of caution should be introduced
at this point.
The operator should be
sure that the test leads are
securely plugged Into
the tip jacks and the alligator clips
securely fastened to the condenser terminals
under
test; otherwise, the
test may indicate an Intermittent
condenser when
the fault Is the result
of a poor con-
nection.
SHORT TEST
If the milliammeter
reading decreases
to a
lower
value
when
the test
clips
are
connected across the condenser,
this Is a positive indication
that the condenser Is not
open. It
is now necessary to determine
by another
test whether the condenser
is shorted.
The push buttons marked "L" and "H"
are
provided
for this test. If it Is known
that the
unknown
capacity
is less than
.003 mfd., then depress push button
"L". If
the capacity is above this value,
then depress push but-
ton "H". If the
meter reading returns to
5
milliamperes,
then
the condenser is shorted. If
the meter reading
decreases,
remains constant,
or increases slightly then
the condenser is not
shorted.
When the
capacity of the condenser
under test is
not known a double check
is necessary. First, depress
button "L"
and then button
"H" and if the condenser
is shorted the meter
reading will return to
5
milliamperes
in each
case. If the meter reading does
not return
to 5 milliamperes in
each case, then the condenser is
not shorted
even though It shows short when
one button
is
depressed. In other words If
a condenser Is shorted
it will show short
in both cases.
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