Service manual

Ultraview 1030/1050 Monitors — Service Manual
4-5
Maintenance
Warning:
Before starting safety tests, ensure that no patient is connected to the device under
test. If safety tests must be performed on equipment currently monitoring a patient,
obtain permission to disconnect the cables from the monitor and patient.
Ground Resistance
1 Attach the power cord to the monitor under test. Then measure the resistance from the AC
power cord third wire ground to a chassis location, such as the equipotential post on the rear of
the monitor.
2 Verify that the resistance is less than 500 milliohms (0.5 ohms).
Chassis Leakage Current Tests
1 Plug the leakage analyzers into mains power.
2 Plug the equipment into the analyzer’s AC receptacle.
3 Verify that the leakage current from the chassis to ground is less than the values in Table 2.
Patient Lead Leakage Current Tests (Patient Modules)
Before you can perform the Patient Lead Leakage Current Test, verify that the monitor passes the
ground resistance and chassis current leakage tests. It is recommended that the equipment be
operating for 30 minutes prior to the test to allow thermal stabilization. If a 12-lead patient cable is
used with the module being tested, perform the tests using the 12-lead cable.
1 Patient Leads Current Leakage — measure the leakage current between each of the patient
leadwires and the ground lug on the monitor back panel. Also, measure the leakage current
between all combinations of ECG leads and ground. The current must be less than 10 μA with
the ground connected, and 50 μA with the ground open.
2 Leakage Current to Ground with 50/60 Hz — AC mains voltage applied to leads. Apply AC
mains voltage and measure the leakage current between each of the ECG leadwires and the
ground lug on the monitor back panel. The current must be less than 50 μA at any line voltage.
Table 2: Enclosure Leakage Test Conditions and Limits
Neutral
Condition
Ground
Condition
Polarity
Internation
al Limit
Domestic
Limit
Closed neutral Closed ground Normal polarity 100 μA 300 μA
Open neutral Open ground Normal polarity 500 μA 300 μA
Closed neutral Open ground Normal polarity 500 μA 300 μA