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installed.
3. After servicing, make the following leakage current checks to
prevent the customer from being exposed to shock hazards.
2.2. Touch-Current Check
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
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
For a. c.: U
For d. c.: U
Note:
The limit value of U
mA (peak) a. c. and 2.0 mA d. c.
The limit value U
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.
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Figure
and U
, does not exceed the following values:
1
2
= 35 V (peak) and U
1
= 1.0 V,
1
= 0.35 V (peak) for a. c. and U
2
= 35 V (peak) for a. c. correspond to the value 70 mA (peak) a. c. for
1
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1.
= 0.35 V (peak);
2
= 1.0 V for d. c. correspond to the values 0.7
1
Figure 1
4
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