4
TGH1266E - 05/04
1 General
What is EDS3065
Critical Use
Before making use of the EDS3065 portable insulation fault location device, the user must have a
very accurate knowledge of its possibilities, the special circumstances relating to its systems, and of
certain hazards which are possible. Among the relevant points to be considered, particular attention
must be paid to the maximum test current. Depending on the switch position of the PGH185, this
is a maximum of 25 mA or 10 mA respectively.
The test current flows between the system and earth, not as a load current. Under unfavourable
combinations of circumstances (low impedance insulation fault in connection with the test cycle
of the test current), control errors cannot be ruled out in the case of sensitive system components
(SPC, relays). Account must be taken of this possibility prior to use. If appropriate, a lower test
current should be set, or the fault location device in this system should not be used.
Attention: the test current of the PGH185 may cause triggering of RCDs. Although the test
current is limited to a maximum of 25 mA (or 10 mA respectively), 30 mA RCD (for example) may
already respond between 15 and 30 mA.
The EDS3065 is a portable insulation fault location device for IT systems (unearthed systems). It
enables insulation faults to be located during operation and without system shutdowns.
The EDS3065 consists of:
• PGH185 Insulation Fault Test Device
• EDS165 Insulation Fault Evaluator
• PSA3020 and PSA3052 Clamp-on Probes
In the past, classical insulation fault location consisted of disconnecting system sections one after
another and then carrying out often laborious and protracted work to search for the faults. Modern
fault location devices such as the EDS3065, PKA3001 or EDS470 (installed as a fixed system) make
the fault location a good deal easier and shorter, and contribute in this way to a better power supply.
While insulation fault location is being undertaken with the EDS3065, any insulation monitoring
device which may be present must be disconnected from the system for the duration of the fault
location, if its internal resistance R is < 120 kΩ. This must be done by effecting an all-pole
interruption of the system coupling - it is not sufficient to switch off the supply voltage to the
insulation monitoring device.
Insulation monitoring devices with an R
i
of 28 kΩ bring about a current conduction against earth
of approximately 14 mA. When a device is used with an R
i
of 120 kΩ the influence is negligible,
and in this case there is no need to disconnect.
The EDS3065 can be used to accomplish the following measurement tasks:
• insulation fault location in IT systems, AC 19.2 ... 575 V / DC 19.2 ... 504 V
• insulation fault location in IT systems, AC 19.2 ... 575 V / DC 19.2 ... 504 V in
combination with an EDS470 insulation fault location device as a fixed installation
• residual current measurement in TT and TN systems (earthed systems)
Danger !
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