GE Medical Systems Dash 3000, Руководство по обслуживанию

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MAINTENANCE: Electrical Safety Tests
Revision B Dash 3000/4000 Patient Monitor 4-11
2000966-105
Power Outlet Test Before starting the tests, the power outlet from which the monitoring
device will get electrical power must be checked. This test checks the
condition of the power outlet to ensure correct results from leakage tests.
For international power outlets, refer to the internal standards agencies
of that particular country. Use a digital multimeter to ensure the power
outlet is wired properly.
If other than normal polarity and ground is indicated, corrective action
must be taken before proceeding. The results of the following tests will be
meaningless unless a properly wired power outlet is used.
Ground (Earth)
Integrity
Listed below are two methods for checking the ground (earth) integrity,
“Ground Continuity Test” and “Impedance of Protective Earth
Connection.” These tests determine whether the device's exposed metal
and power inlet's earth (ground) connection has a power ground fault
condition.
Perform the test method below that is required by your Country/Local
governing safety organization.
Ground Continuity Test Completion of this test is checked by the following steps:
1. Disconnect the device under test from the power outlet.
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). Refer to the US
120Vac power cord figure above.
3. Set the DMM to the milliohm (m
Ω
) range.
4. Connect the positive (+) lead of the DMM to all exposed metal
surfaces on the device under test. If the metal surfaces are anodized
or painted, scrape off a small area in a inconspicuous place for the
probe to make contact with the metal.
5. Resistance must read:
• 0.1 ohm or less without power cord
• 0.2 ohms or less with power cord