Operation Manual

GMC-I Messtechnik GmbH 65
21 Appendix
21.1 Evaluation of Measured Values for Individual Measurements
as well as for Calculated Quantities
In order to assure that the limit values for the individual measurements
are always observed, device measuring error must be taken into
consideration.
The table in the appendix allows for calculation of the required minimum
display value for each respective measurement which must appear at the
instrument in consideration of measuring error (under nominal conditions
of use), in order to assure that the required limit value is not fallen short of
(DIN VDE 0413, part 1). Intermediate values can be interpolated.
Measuring Error for Test Sequences
The test instrument takes respective measuring error into consideration
during automatic test sequences, and corrected results are entered into
the test report, as long as this function has been activated in the setup
menu under “include service error”.
Omitting the Protective Conductor Test in the Case of Fully Insulated Devices
You are testing a fully insulated safety class I device (e. g. screen, sub-
mersible pump, etc.), which is not equipped with an external protective
conductor contact.
The decision as to the necessity of a protective conductor test in this case is
to be taken by a qualified electrician who should also assume responsibility.
You can omit the protective conductor test by pressing the key as soon
as the following instruction is shown: „Please connect the probe with the
protective conductor of the DUT“.
Tables for the calculation of minimum display values for insulation
resistance and maximum display values for protective conductor resis-
tance, equivalent leakage current, probe current and residual current in
consideration of device measuring error:
1)
Depending upon resolution
21.2 Evaluation of Measured Values during Equivalent Leakage Current
Measurement (Automatic Test Sequence According to Standard)
During equivalent leakage current measurement, L and N are intercon-
nected whereupon a test voltage of 230 V is applied between LN and PE
and the leakage current is measured. Thus the most adverse case (N in-
terrupted) is being tested.
As a rule, this results in at least double the value of the direct leakage cur-
rent measurement (since all discharge capacitors are placed in parallel).
If frequency converters are used in addition to that, it is no longer possible
to compare the measured values between direct leakage current and
equivalent leakage current method. In this case, we recommend conduct-
ing individual measurements in accordance with the residual current
method.
R
INS
M R
PE

Limit Value
Minimum
Display Value
Limit Value
Maximum
Display Value
0.100 0.115 0.100 0.085
0.250 0.273 0.200 0.180
0.500 0.535 0.300 0.275
1.000 1.060 0.400 0.370
2.000 2.200 0.500 0.465
5.000 5.350 0.600 0.560
7.000 7.450 0.700 0.655
10.00 10.60 or 12.5
1)
0.800 0.750
20.00 23.00 0.900 0.845
75.00 83.50 1.000 0.940
1.100 1.035
I
EL
mA I
probe
mA I mA
Limit Value
Maximum
Display Value
Limit Value
Maximum
Display Value
Limit Value
Maximum
Display Value
1.00 0.85 0.100 0.085 0.25 0.12
3.50 3.23 0.250 0.227 0.50 0.35
7.00 6.55 0.500 0.465 1.00 0.80
10.00 9.40 1.000 0.940 2.00 1.70
15.00 14.15 2.000 1.890 3.50 3.05
20.00 18.90 3.500 3.315 5.00 4.40
7.00 6.20
10.00 8.90
15.00 13.40
20.00 17.90
25.00 22.40