FMP-X10 iv
LEAKAGE TEST
The AC leakage from any exposed metal part to earth ground and from all
exposed metal parts to any exposed metal part having a return to chassis,
must not exceed 0.5 mA (500 microamperes). Leakage current can be
measured by any one of three methods.
1.
A commercial leakage tester.
Follow the manufacturers’ instructions provided with the tester.
2.
A battery-operated AC milliammeter.
3.
Measuring the voltage drop across a resistor by means of a VOM
or battery-operated AC voltmeter. The “limit” indication is 0.75 V, so
analog meters must have an accurate low voltage scale. Nearly all
battery-operated digital multimeters that have a 2 VAC range are
suitable. (see Figure A)
To Exposed Metal
Parts on Set
0.15 µF
Earth Ground
AC
Voltmeter
(0.75V)
Figure A. Use an AC voltmeter to check AC leakage.
HOW TO FIND A GOOD EARTH GROUND
The cover-plate retaining screw on most AC outlet boxes is at earth ground.
Verify the AC outlet box retaining screw ground by connecting a 60W to
100W incandescent (not a neon or fluorescent lamp) between the hot side of
the receptacle and the retaining screw. Try both slots, if necessary, to locate
the hot side on the line; the lamp should light at normal brilliance if the screw
is at ground potential. (see Figure B)
Figure B. Checking for earth ground.
Trouble Light
AC Outlet Box
