GE HEALTHCARE CARESCAPE Monitor B650 Technical Manual page 111

Acceptance criteria:
• 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.
b) Impedance of protective earth connection
This test is normally 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 doubt.
Check compliance as follows:
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 seconds, but not more than 10 seconds,
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.
When taking this measurement, flex the unit's power cord along its length. There should
be no fluctuations in resistance.
Acceptance criteria:
• 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.
Installation checkout
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