Safety Check After Servicing - Hitachi VTFX340EUK Service Manual

1-1-3 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 their original posi-
tions. Afterwards, do the following tests and confirm
the specified values 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. 1-1-1)
Table 1-1-1 : Ratings for selected area
AC Line Voltage
230 V
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
between B (earth ground, power cord plug prongs)
and externally exposed accessible parts (RF termi-
nals, antenna terminals, video and audio input and
output terminals, microphone jacks, earphone jacks,
etc.) is lower than or equal to the specified value in the
table below.
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 the terminals of load
Z. See Fig. 1-1-2 and the following table.
Table 1-1-2: Leakage current ratings for selected areas
AC Line Voltage
230 V
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
1-2
Clearance Distance (d) (d')
≥
3 mm(d)
≥
6 mm(d')
Load Z
2kΩ RES.
Connected in parallel
50kΩ RES.
Connected in parallel
Exposed Accessible Part
Z
One side of
B
Power Cord Plug Prongs
Leakage Current (i)
i≤0.7mA AC Peak
i≤2mA DC
i≤0.7mA AC Peak
i≤2mA DC
Chassis or Secondary Conductor
Primary Circuit Terminals
d' d
AC Voltmeter
(High Impedance)
One side of power cord plug
prongs (B) to:
RF or
Antenna terminals
A/V Input, Output
Fig. 1-1-1
Fig. 1-1-2