LEAKAGE TEST (FOR SERVICE ENGINEERS
IN
THE U.S.A.)
Before returning the unit to the user, perform the following safety checks:
1.
Inspect all lead dress to make
certain that leads are not pinched
or that hardware
is
not lodged be-
tween
the
chassis
and
other
SIMPSON MODEL 229 ETC. FOR
LEAKAGE TEST
metal parts
in
the unit.
TO
EACH EXPOSED
2.
Be sure that any protective de-
vices such as nonmetallic control
knobs,
insulating
fishpapers,
cabinet
backs, adjustment and
METAL SURFACE OF
._
__
----1
UNIT UNDER TEST
compartment covers or shields,
isolation
resistor-capacity
net-
works,
mechanical
insulators,
etc. Which were removed for ser-
vicing are properly reinstalled.
3.
Be
sure that
no
shock hazard exists; check for leak-
age current using Simpson Model 229 Leakage
Tester, standard equipment item No. 21641, RCA
Model WT540A or use alternate method as follows:
Plug the power cord directly into a 120-volt AC re-
ceptacle (do not use an Isolation Transformer
for
this test). Using two clip leads, connect a 1500
Ohm, 10-watt resistor paralleled by a 0.15µF ca-
pacitor, in series with all exposed metal cabinet
parts and a known earth ground, such as a water
pipe
or
conduit. Use a VTVM
or
VOM with 1000
Ohms per volt, or higher sensitivity to measure the
HIGH
VOLTAGE
OR+
LEAD
TEST PROBE
AC
voltage drop across the resistor. (See Diagram.) TO EXPOSED
Move the
resistor
connection
to each exposed METAL PARTS
metal part having a return path to the chassis (an-
tenna, metal, cabinet, screw heads, knobs and con-
trol shafts, escutcheon, etc.) and measure the AC
voltage drop across the resistor. (This test should
be performed with the power switch
in
both the On
and Off positions.)
1.5k
10W
0.15µ
F
TO AC GROUND SUCH
GROUND
AS
WATER PIPE, BX CABLE.
LEAD CONDUIT, ETC.
CONNECT TO KNOWN
EARTH GROUND
A reading of 0.35 volt
RMS
or more is excessive and indicates a potential shock hazard which must
be
corrected
before returning the unit to the owner.
4
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