Operation Manual

GMC-I Messtechnik GmbH 27
11.3 Patient Leakage Current I
PL
Current which flows from an ap-
plication part via the patient to
earth. This current may be caused
by an unintentional interference
voltage at the patient, and may
flow via the patient and an insu-
lated, floating type F application
part to earth. Useful patient cur-
rent is excluded in both cases.
AC and DC components are measured.
Note
+
Patient leakage current must also be measured if application
parts are available.
The displayed test voltage must be documented.
11.4 Patient Auxiliary Current I
PA
(Feature KA01)
Current which flows within the
patient between the electrodes of
the application part. Use for in-
tended purpose is assumed. Fur-
thermore, the current should not
cause any physiological effects.
For example, this is the case for
input current from amplifiers, or
current used for impedance
plethysmography.
AC and DC components are measured.
11.5 Residual Current I
RC
Sum of instantaneous current values which flow via the L and N conduc-
tors at the device mains connection (also known as differential current).
Residual current is practically identical to fault current in the event of an er-
ror. Fault current: Current which is caused by an insulation defect, and
which flows via the defective point.
11.6 Device Leakage Current I
LC
per IEC 62353 (VDE 0751-1)
Device leakage current is the
sum of all leakage currents from
the housing, all accessible
conductive parts and all applica-
tion parts to PE. Measurement
must be performed for both
mains polarities and the largest
value is documented.
Note
+
The highest device leakage current value and line voltage must
be documented.
Attention!
!
The protective conductor is interrupted during this
measurement.
2
3
(N) L
(L) N
1 Test socket w/o
protective conduc-
tor contact
2 Application part
3 Device housing
4 Measuring circuit

4
IEC 62353/
I
LC
1
VDE 0751