Safety instructions
Safety instructions
iso685-D-P_D00170_03_M_XXEN/07.2017
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Prevent measurement errors!
When a monitored IT system contains galvanically coupled DC circuits, an
insulation fault can only be detected correctly if the rectifier valves (e.g.
rectifier diode, thyristors, IGBTs, frequency inverters, …) carry a minimum
current of > 10 mA.
Unspecified frequency range
When connecting to an IT system with frequency components below the
specified frequency range, the response times and response values may
differ from the indicated technical data. However, depending on the ap-
plication and the selected measurement method, continuous insulation
monitoring is also possible in this frequency range.
There is no influence on the insulation monitoring for IT systems with fre-
quency components above the specified frequency range, e.g. within the
range of typical switching frequencies of frequency inverters (2…20 kHz).
2.4 Intended use
The ISOMETER® monitors the insulation resistance of unearthed AC/DC main circuits (IT
systems) with mains voltages of AC 0…690 V or DC 0…1000 V.
DC components existing in AC/DC systems do not influence the operating characteristics.
A separate supply voltage allows de-energised systems to be monitored too. The maxi-
mum permissible system leakage capacitance is 0…1000 µF, depending on the profile.
In combination with an insulation fault locator (EDS), the ISOMETER® can be used for in-
sulation fault location. By means of measuring current transformers, the EDS detects the
locating current pulses generated by the ISOMETER® in unearthed DC, AC and three-
phase power supplies (IT systems) and evaluates them.
Intended use also implies:
• The observation of all information in the operating manual
• Compliance with test intervals
In order to meet the requirements of applicable standards, customised parameter set-
tings must be made on the equipment in order to adapt it to local equipment and oper-
ating conditions. Please heed the limits of the area of application indicated in the
technical specifications.
Any other use than that described in this manual is regarded as improper.
Only qualified personnel are permitted to carry out the work necessary
to install, commission and run a device or system.
iso685-D-P_D00170_03_M_XXEN/07.2017
12
Function
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