GE Vivid in, Service Manual

Page: 729 / 740

GE H
EALTHCARE
D
IRECTION
FQ091013, R
EVISION
1 V
IVID
I
N AND
V
IVID Q
N S
ERVICE
M
ANUAL
Chapter 10 - Care and Maintenance 10-27
10-7-6
Isolated Patient Lead (Source) Leakage – Lead-to-Ground
10-7-6-1 Definition
This test measures the current which would flow to Ground from any of the isolated ECG leads. The
meter simulates a patient who is connected to the monitoring equipment and is grounded by touching
some other grounded surface.
Measurements should be made with the Ground open and closed , with power line polarity normal and
reversed , and with the ultrasound console OFF and ON. For each combination the operating controls,
such as the lead switch, should be operated to find the worst case condition.
CAUTION:
Equipment damage possibility. To avoid damaging the unit, never switch the polarity and
the neutral status when the unit is powered ON. Be sure to turn the unit power OFF before switching
them, using the
Polarity
switch and/or the
Neutral
switch.
10-7-6-2 Generic Procedure
Measurements should be made with the Ground
Open
and
Closed
, with power line polarity
Normal
and
Reversed
, and with the Vivid i n/ Vivid q N unit
ON
and
OFF
. For each combination, the operating
controls (such as, the lead switch) should be operated to find the worst case condition.
.
Figure 10-4 Test Circuit for Measuring Non-Isolated Patient Leads
POWER
OUTLET
H (Black)
N (White)
G (Green)
Internal
circuitry
Insulating surface
Polarity reversing switch
(use both positions)
Appliance power switch
(use both "OFF" and "ON" positions)
Patient connected leads
The connection is at service entrance
or on the supply side of a separately
derived system
Building
Ground
Grounding contact switch (use in both
"open" and "closed" positions)
Current meter
H = Hot
N = Neutral (grounded)
G = Grounding conductor
H
N
G
Patient lead selector switch (if any)
(activated as required)
Appliance
Between each patient
lead and Ground