12-12
12.9 Electrical Safety Inspection
NOTE
Perform electrical safety inspection after servicing or routine maintenance. Before
the electrical safety inspection, ensure all the covers, panels, and screws are
correctly installed.
The electrical safety inspection should be performed once a year.
1. Perform protective earth resistance test:
a. Plug the probes of the analyzer into the protective earth terminal of the AC power
cord and the screw.
b. Test the earth resistance with a current of 25A.
c. Verify the resistance is less than 0.1ohms (100 mohms).
d. If the resistance is larger than 0.1ohms (100 mohms) but less than 0.2ohms (200
mohms), disconnect the AC power cord and plug the probe, that was previously plugged
in the protective earth terminal of the AC power cord, into the protective earth contact of
the power outlet. Repeat steps a to c.
2. Perform the following earth leakage current tests:
normal polarity
reverse polarity
normal polarity with open neutral; and
reverse polarity with open neutral.
3. Verify the maximum leakage current does not exceed 500 μA (0.5 mA) in the first two
tests. While for the last two tests, verify that the maximum leakage current does not
exceed 1000 μA (1 mA).
NOTE
Ensure the safety analyzer is authorized by certificate organizations (UL, CSA, or
AAMI etc.). Follow the instructions of the analyzer manufacturer.
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