GE ApexPro TT Technical Manual page 147

2001989-351A
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 tests
Perform this test to measure current leakage through the ground (earth) wire of the
equipment during normal operation.
NOTE
The DMM plus leakage tester network shown is the circuitry defined by the UL
60601-1 standard for measuring leakage current.
The measuring devices, defined by various standard organizations (IEC, UL,
etc.), produce almost identical test measurement results.
1. Configure the leakage tester like the circuit shown below.
2. Connect the power cord of the device under test to the power receptacle on the
leakage tester.
3. The device under test is to be tested at its normal operating voltage.
4. Set the power switch of the device under test to ON.
5. Read the current leakage indicated on DMM.
6. Set the polarity switch on the leakage tester to RVS (reverse).
7. Read the current leakage indicated on DMM.
ApexPro™
Checkout
GND wire leak
7-9