FISCHER MD-1a, Technical Reference Manual, Page: 7 / 10

Electrical Device Inspection
Period: Annually (12 months)
Line Voltage , Ground Integrity:
◊
Measure line voltage supplied to the device . Accept: 105-120 VAC
◊
Confirm reliable ground connection by ensuring line receptacle is 3-prong grounded
type and ground integrity is intact.
Accept: Ground OK
◊
Measure device ground wire resistance between line plug ground contact and the
screw near the Heyco cord grip on the rear panel.
Accept: 0 to 1.0 ohm
Nominal reading is .1-.2 ohms. IMPORTANT: Do not make this measurement
between line plug ground contact and front or rear panel surfaces; these panels are
anodized and will not conduct.
Chassis and Patient Leakage:
◊
Measure ground leakage between line and chassis using an approved Electrical
Safety Analyser. Use screw head near the Heyco cord grip on the rear panel for
chassis connection.
Accept: Less than 50uA
IMPORTANT: Do not make this measurement between line and front or rear panel
surfaces; these panels are anodized and will not conduct.
Nominal readings appear below for reference.
Normal Polarity-Normal Ground: 5 uA
Reverse Polarity-Normal Ground: 5 uA
Normal Polarity-Open Ground: 10 uA
Reverse Polarity-Open Ground: 10 uA
◊
Measure patient lead leakage between line and red and black Output Jacks using an
approved Electrical Safety Analyser.
Accept: Less than 50uA
Nominal readings appear below for reference.
Normal Polarity-Normal Ground: 5 uA
Reverse Polarity-Normal Ground: 5 uA
Normal Polarity-Open Ground: 5 uA
Reverse Polarity-Open Ground: 5 uA
Dielectric Strength Test (OPTIONAL):
◊
Apply 1250 VAC, 60 Hz between line and chassis ground for 60 seconds using an
approved Dielectric Withstand Tester, with Cutoff current set to 1.0-2.0 ma.
◊
Apply 1250 VAC, 60 Hz between line and patient leads (red and black jacks) for 60
seconds using an approved Dielectric Withstand Tester with Cutoff current set to 1.0-
2.0 ma.
Accept: No Breakdown
IMPORTANT: Observe safety precautions when conducting dielectric strength test.
Do not return to service any device which has failed the withstand test as it may have
become internally damaged. This test is optional and does not need to be conducted
annually.
DEVICE INSPECTION
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