Gossen Metrawatt Metrahit Iso Insulation measuring device, CAT III 600 V Metrahit Iso Benutzerhandbuch

Produktcode
Metrahit Iso
Seite von 72
GMC-I Gossen-Metrawatt GmbH
41
Measurements: V/Hz, 
Ω,  , Temp (°C/°F), 
, M
Ω
@UISO
, A/Hz
Automatic Recognition of Interference Voltage 
during Insulation Resistance Measurement
If the instrument detects interference voltage of greater than 
15 V AC or > 25 V DC during insulation testing (condition: U
interference
 
≠ U
ISO
, e.g. Riq < 100 k
Ω at 100 V, see Seite 58, footnote 1), 
ERROR is briefly displayed at the LCD. The instrument is then 
automatically switched to voltage measurement, and the currently 
measured voltage value is displayed.
Note

A dead zone results in erroneous measurements for 
automatic interference voltage detection. The dead zone lies 
within a range of 80% to 120% of the selected test voltage 
(in the case of an interference voltage whose value is equal 
to that of measuring voltage, the two voltages neutralize 
each other).
Manual switching to insulation resistance measurement is 
disabled for as long as voltage is applied to the test terminals. 
If interference voltage is no longer present, the M
Ω
@ISO
 
measurement can be started by once again pressing the 
U
ISO
 ON / OFF key.
Attention!
!
If ERROR appears at the display, the cable (the device 
under test) is most likely capacitively charged to a 
significant extent. 
Remedy: 
Short circuit the cable (the device under test). Repeat the 
measurement.
5.7.3 Ending the Measurement and Discharging 
➭ Briefly press the U
ISO
 ON / OFF key.
After measurement has been completed, any remaining residual 
voltage is displayed which may result from cable capacitance. 
The instrument’s internal 100 M
Ω resistor causes rapid 
discharging. However, contact to the device under test must be 
maintained. The falling voltage value can be observed directly at 
the LCD. Do not disconnect the device under test until the voltage value 
has dropped to < 25 V!
Note

The instrument’s batteries are rapidly depleted during 
insulation resistance measurement. Deactivate insulation 
resistance measurement between measurements for this 
reason. Use only alkaline manganese batteries in 
accordance with IEC 6 LR61.
Note

Rotary selector switch position “V 1
M
Ω / 
M
Ω
@UISO
” is 
available for the detection of interference voltage during 
insulation resistance measurement.
Us switch position V
, V
  or V
 in order to perform 
precise voltage measurements.
+
0 V  !
Discharge
025.0
U
ISO
V
DC
AC
TRMS
ISO 500 V