Protective Earth Resistance Test; 7.1.3.3. Measurement Of Leakage Current; Enclosure Leakage Current Test - GE MAC 1200 Servicing Instructions

GE Medical Systems MAC 1200 V 1.2 Page 58
Information Technologies 227 492 21 Rev F
7.1.3.2 Protective Earth Resistance Test
The power cord is to be included in the protective earth resistance test.
This test determines whether the device has a power ground fault.
- The protective earth resistance from power connector to any protective earth
connected exposed conductive part is measured.
- Specs. of test circuit: AC current source 50 Hz/60 Hz of at least 10 A up to 25 A
with limited output voltage of 6 V.
- If resistance is greater than 100 mOhm,
the unit fails this test.
10k
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0,015 UF i
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7.1.3.3. Measurement of Leakage Current
To perform the suggesied measurements, the
unit being tested has to be separated from any interconnection to a system. If the unit is
part of a system, extended tesis according to IEC 601-1-1 have to be performed. The
following diagram shows the
Measuring Circuit [M] required for leakage current. The reading in mV corresponds to LA
(leakage current). The Safety Testers generally work with this Measuring Circuit [M] and
the displayed values are already converted to leakage current.
7.1.3.3.1 Enclosure Leakage Current Test
This test is performed to measure leakage current from chassis to ground during normal
condition (N.C.) and single fault conditions (S.F.C.).
In all cases, the leakage current is measured from any exposed conductive parts to ground,
the unit being tested has to be switched on and off.
Connect the unit being tested to your Safety Tester.
- During normal condition (N.C.), referring to the electrical diagram, measurements have to
be done under the following conditions:
* Polarity switch Norm and RVS
* GND switch GND closed
* $1 closed and open