Document Number PD196-068 R1
14 October 2004
Page 19 of 24
Safety Checks
Before returning the P10LCD to service, the following safety checks should be performed.
1. PARTS
PLACEMENT
Confirm that the screws, parts, and wiring which were removed to allow servicing are put
back in the original positions.
2. SWIVEL RESISTANCE TEST
1. Expose the mounting swivel.
2. Measure the DC resistance between
the input coax shield and swivel as
shown. The resistance value should
read greater than 1 Meg. A lesser
reading indicates a possible
insulation breakdown or short
between the internal metal U-
Bracket and chassis ground which
could increase leakage currents
touchable by the patient.
3. It is recommended that the reading
of the swivel resistance be recorded
as part of the service record.
3. AC LEAKAGE CURRENT TEST
Following re-assembly of the P10LCD
always perform an AC Leakage Current
Test. Use either an approved hospital
leakage meter or the R-C network shown.
SWIVEL LEAKAGE
a. Power the TV using an approved
external 28 VAC power supply. DO
NOT USE A LINE ISOLATION
TRANSFORMER DURING THIS
TEST.
b. Connect one side of the R-C network
to a good earth ground such as a
water pipe, conduit, etc. Touch the
other side of the R-C network to the
top of the metal swivel.
c. Measure the AC voltage drop across
the R-C network. The measured
voltage must not exceed 0.10 volts
RMS (100 millivolts RMS). This
corresponds to 100 microamperes of
AC current. Any value exceeding this
limit constitutes a potential shock
hazard and must be correct
immediately.
d. Record the reading as part of the
service record.
> 1 Meg
1,000 ohm
.15 MFD
< 100 millivolt
