Preventive maintenance
2026419-033E CIC Pro™ 10-7
2. Connect the negative (-) lead of the DMM to the protective earth terminal
(ground pin in power inlet connector) or the protective earth pin in the Mains
plug (ground pin in power cord).
3. Set the DMM to the milliohm (mW) range.
4. Connect the positive (+) lead of the DMM to the equipotential plug on the CIC
Pro center.
5. Resistance must read:
0.1 ohm or less without power cord
0.2 ohms or less with power cord
Impedance of protective earth connection test
This test, unlike a ground continuity test, will also stress the ground system by using
special ground bond testers. This test normally is only required as a manufacturing
production test to receive safety agency compliance. Some country agencies do
require this test after field equipment repairs (i.e., Germany's DIN VDE 0751
standards). Consult your country/local safety agency if in question.
1. A current of 25A from a current source with a frequency of 50 or 60 Hz with a
no-load voltage not exceeding 6 V is passed for at least 5 s through the protective
earth terminal or the protective earth pin in the mains plug and each accessible
metal part which could become live in case of failure in basic insulation.
2. The voltage drop between the parts described is measured and the impedance
determined from the current and voltage drop. It shall not exceed the values
indicated.
For equipment without a power supply cord the impedance between the protective
earth terminal and any accessible metal part which is protectively earthed shall not
exceed 0.1 ohms.
For equipment with a power supply cord, the impedance between the protective earth
pin in the mains plug and any accessible metal part which is protectively earthed shall
not exceed 0.2 ohms.
When taking this measurement, move the unit's power cord around. There should be
no fluctuations in resistance.
Ground (earth) wire leakage current test
NOTE
The DMM plus leakage tester network shown is the circuitry defined by the IEC/
EN/UL 60601-1 standard for measuring leakage current.
Perform this test to measure current leakage through the ground (earth) wire of the
equipment during normal operation.
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