2.2. Touch-Current Check
2 Safety Precautions
2.1. General Guidelines
1. When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated or
damaged by the short circuit.
2. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly
installed.
3. After servicing, make the following leakage current checks to prevent the customer from being exposed to shock hazards.
1. Plug the AC cord directly into the AC outlet. Do not use an isolation transformer for this check.
2. Connect a measuring network for touch currents between each exposed metallic part on the set and a good earth ground such
as a water pipe, as shown in Figure 1.
3. Use Leakage Current Tester (Simpson 228 or equivalent) to measure the potential across the measuring network.
4. Check each exposed metallic part, and measure the voltage at each point.
5. Reserve the AC plug in the AC outlet and repeat each of the above measure.
6. The potential at any point (TOUGH CURRENT) expressed as voltage U
1
and U
2
, does not exceed the following values:
For a. c.: U
1
= 35 V (peak) and U
2
= 0.35 V (peak);
For d. c.: U
1
= 1.0 V,
Note:
The limit value of U
2
= 0.35 V (peak) for a. c. and U
1
= 1.0 V for d. c. correspond to the values 0.7 mA (peak) a. c. and 2.0
mA d. c.
The limit value U
1
= 35 V (peak) for a. c. correspond to the value 70 mA (peak) a. c. for frequencies greater than 100 kHz.
7. In case a measurement is out of the limits specified, there is a possibility of a shock hazard, and the equipment should be
repaired and rechecked before it is returned to the customer.
Figure 1
6
TH-42PA50E / TH-42PE50B / TH-37PA50E / TH-37PE50B
Summary of Contents for TH-37PA50E
Page 5: ...1 Applicable signals 5 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 17: ...7 Location of Lead Wiring 7 1 Lead of Wiring 1 17 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 18: ...7 2 Lead of Wiring 2 18 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 19: ...7 3 Lead of Wiring 3 19 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 22: ...8 3 No Picture 22 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 25: ...25 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 26: ...9 3 Option Description 26 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 27: ...27 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 31: ...10 5 Test Point Location 31 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 36: ...36 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 132: ...15 2 Packing Exploded Views 1 132 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 133: ...15 3 Packing Exploded Views 2 133 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
Page 134: ...15 4 Packing Exploded Views 3 134 TH 42PA50E TH 42PE50B TH 37PA50E TH 37PE50B ...
