UNITED TVC5044, Service Manual

Page: 8 / 92

1-2-4 T6600SFTY
Safety Check after Servicing
Examine the area surrounding the repaired location for
damage or deterioration. Observe that screws, parts
and wires have been returned to original positions.
Afterwards, perform the following tests and confirm the
specified values in order to verify compliance with
safety standards.
1. Clearance Distance
When replacing primary circuit components, confirm
specified clearance distance (d) and (d') between sol-
dered terminals, and between terminals and surround-
ing metallic parts. (See Fig. 1)
Table 1 : Ratings for selected area
Note: This table is unofficial and for reference only.
Be sure to confirm the precise values.
2. Leakage Current Test
Confirm the specified (or lower) leakage current be-
tween B (earth ground, power cord plug prongs) and
externally exposed accessible parts (RF terminals, an-
tenna terminals, video and audio input and output ter-
minals, microphone jacks, earphone jacks, etc.).
Measuring Method : (Power ON)
Insert load Z between B (earth ground, power cord
plug prongs) and exposed accessible parts. Use an
AC voltmeter to measure across both terminals of load
Z. See Fig. 2 and following table.
Table 2: Leakage current ratings for selected areas
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
AC Line Voltage Clearance Distance (d), (d’)
220 to 240 V
≥
3mm(d)
≥
6 mm(d’)
Chassis or Secondary Conductor
d d’
Primary Circuit Terminals
Fig. 1
Fig. 2
AC Voltmeter
(High Impedance)
Exposed Accessible Part
B
One side of
Power Cord Plug Prongs
Z
AC Line Voltage Load Z Leakage Current (i)
One side of power cord plug
prongs (B) to:
220 to 240 V
2k
Ω
RES.
Connected in
parallel
i
≤
0.7mA AC Peak
i
≤
2mA DC
RF or
Antenna terminals
50k
Ω
RES.
Connected in
parallel
i
≤
0.7mA AC Peak
i
≤
2mA DC
A/V Input, Output