Hitachi VT-FX685A, Service Manual, Page: 5 / 67

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 positions.
Afterwards, do the following tests and confirm the speci-
fied 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)
Table 1 : Ratings for selected area
AC Line Voltage Clearance Distance (d) (d’)
120 V
≥
3.2 mm (0.126 inches)
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.) 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. 2 and the following table.
Table 2 : Leakage current ratings for selected areas
AC Line Voltage Load Z Leakage Current (i) Earth Ground (B) to:
120 V
0.15
µ
F CAP. & 1.5k
Ω
RES.
Connected in parallel
i
≤
0.5mA Peak Exposed accessible parts
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
Chassis or Secondary Conductor
d d'
Primary Circuit Terminals
Fig. 1
AC Voltmeter
(High Impedance)
Exposed Accessible Part
B
Earth Ground
Power Cord Plug Prongs
Z
1.5k
Ω
0.15
µ
F
Fig. 2
1-2-2