DMR-ES10EB / DMR-ES10EC / DMR-ES10EG / DMR-ES10EP / DMR-ES10EBL
1 Safety precautions
1.1. 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.
1.1.1. Leakage current cold check1.1.2. Leakage current hot check
(See Figure 1 .)
1. Unplug the AC cord and connect a jumper between the two
prongs on the plug. 1. Plug the AC cord directly into the AC outlet. Do not use an
2. Measure the resistance value, with an ohmmeter, betweenisolation transformer for this check.
the jumpered AC plug and each exposed metallic cabinet 2. Connect a 1.5k&, 10 watts resistor, in parallel with a 0.15?F
part on the equipment such as screwheads, connectors,capacitors, between each exposed metallic part on the set
control shafts, etc. When the exposed metallic part has aand a good earth ground such as a water pipe, as shown in
return path to the chassis, the reading should be betweenFigure 1.
1M& and 5.2M&. 3. Use an AC voltmeter, with 1000 ohms/volt or more
When the exposed metal does not have a return path tosensitivity, to measure the potential across the resistor.
the chassis, the reading must be. 4. Check each exposed metallic part, and measure the
voltage at each point.
5. Reverse the AC plug in the AC outlet and repeat each of the
above measurements.
6. The potential at any point should not exceed 0.75 volts
RMS. A leakage current tester (Simpson Model 229 or
equivalent) may be used to make the hot checks, leakage
current must not exceed 1/2 milliampere. In case a
measurement is outside of the limits specified, there is a
possibility of a shock hazard, and the equipment should be
Figure 1repaired and rechecked before it is returned to the
customer.
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ACEC
