EDS470 - Bender

System c omponents
With or without PRC470
The modular EDS470 system offers the possibility to realize an economical
insulation fault location with minimum equipment. This minimum equipment
consists of
• insulation monitoring device of the IRDH265-4/365-4 or IR475LY series
(possibly already available)
• insulation fault test device PGH471
• insulation fault evaluator EDS470-12
• respective number of measuring current transformers
Such a system can be used in simple interference-free IT systems without
complex components.
In operation without the PRC470 and without a serial connection to the PGH471,
the EDS470-12 scans all the connected transformers in a rhythm of 25 seconds,
even though the PGH471 insulation fault test device is not running. In this case,
faults (I∆ > 10 A or interferences) can also be signalled.
However, if significant interferences occur in the system, and EDS470 system
with PRC470 must be used in any case.
Typical causes of interferences are e.g. converters with low-frequency leakage
currents or switchgears and controls which produce transient leakage currents.
For further information see chapter LIMITS OF INSULATION FAULT LOCATION.
Apart from the control functions and the extended scanning possibilities, the
PRC470 allows for adapting the EDS470 system to different system parameters. In
addition, it makes the entire EDS470 system more comfortable and easier to use.
It is generally possible to retrofit an existing EDS470 system without PRC470 with
a PRC470, if this becomes necessary due to modifications in the system.
Already during planning, the considerations and the decision for an EDS470
system with or without PRC must be made. In case of doubt, an EDS470 system
with PRC470 must always be preferred. Ask for technical help from Bender if
there are uncertainties.
If one or more of the following points apply, it is necessary to use a PRC470:
• IT systems with interferences caused by frequency converters, PLCs,
clocked control.
• Requirement for central scanning of all connected insulation fault
evaluators.
• Requirement for central control of all connected insulation fault evaluators
and test devices.
• Setting of different types of measuring current transformers.
• Limitation of the current transformer scanning for each insulation fault
evaluator.
• Display of the test current for each measuring current transformer.
• Targeted scanning of one measuring current transformer.
• Serial connection to PCs by means of RS485 interface.
• Requirement for central test functions.
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TGH 1243E/02.2000