Operation Manual

GMC-I Messtechnik GmbH 7
Attention!
!
Contact Hazard
Do not touch the conductive ends of the test prods when the in-
strument has been activated for the measurement of insulation
resistance.
This may cause current to flow over your body, which, although it
does not reach life endangering levels, causes a clearly discern-
ible shock.
When measurements are made at capacitive devices under test,
e.g. cables, the DUT may be charged with voltages of up to ap-
proximately 5000 V, depending upon selected nominal voltage.
Contact with the device under test after measurement is, in this
event, life endangering!
Safe Discharge
For this reason the DUT must be discharged in a controlled fash-
ion by switching to V and contacting the DUT with the test prods
until the measurement display indicates 0 V. Do not reverse the
poles of the DUT during discharging, because internal overvolt-
age protection would otherwise be triggered. If the capacity to be
discharged is greater than 3 F, the poles may absolutely not be
reversed, because the device might otherwise be damaged.
Note

Overvoltage Influence
If the reversible fuse (PTC thermistor) responds to an overvoltage
or an extraneous voltage, measurement may not be resumed
immediately. A cool-down period of approximately 2 minutes must
be observed.
5.2 Evaluation of Measurement Values
In order to assure that insulation resistance values do not fall below those
required by DIN VDE regulations, insulation tester inherent deviation and
influence errors must be taken into consideration. Required minimum dis-
play values for insulation resistance which take maximum operational
measurement deviation of the METRISO PRIME into consideration (under
nominal conditions of use) can be determined with the following table.
These are the minimum values which must be displayed, in order to
assure that actual values do not fall below the required limit values. Inter-
mediate values can be interpolated.
The table is valid for test voltages ranging from 100 V ... 1000 V.
Scale, 100 k ... 100 M
Limit Value
[k]
Display Value
[k]
100 130
200 260
300 400
400 550
500 700
Limit Value
[M]
Display Value
[M]
11.3
22.6
34
45.5
57
10 13