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TGH1266E - 05/04
Practical Use
Using the EDS165
within an EDS470
system
The EDS165 insulation fault evaluator can also be used without the PGH185 test device within
a system such as an EDS470, as a fixed installation. In this case, it detects the test pulses from the
PGH470 test device. Insulation fault evaluation is only possible in voltage-operating IT systems.
The practical use of the EDS165 within a fixed EDS470 insulation fault location device is
described below:
• The central insulation monitor has reported an insulation fault below its response value.
• The insulation fault location device is activated and it starts the fault search; the test
device is generating the test current. The insulation fault evaluation continues as long
as the test device is clocking.
• Connect the clamp-on probe or the measuring current transformer (via a BNC
adapter).
• Move the operating mode switch of the EDS165 to the I
∆s
position; wait until the basic
menu appears on the display.
• Check whether the correct nominal frequency for the network is set. The factory
setting for the frequency is 50 Hz.
• Check whether the correct clamp-on probe and/or the correct measuring current
transformer are set in menu 4 (m4 - set sensor). The factory setting is clamp-on probe
PSA3052.
• At junctions where no measuring current transformer is installed, or downstream of
installed measuring current transformers, the search can now be continued with the
EDS165. Attention: do not connect the core of the clamp-on probe to system voltages
above the nominal insulation voltage.
• All system conductors, but not the PE, must be encircled by the clamp-on probe.
Attention: do not encircle any shielded leads!
• When the clamp-on probe is encircling ’live’ conductors, it must not be disconnected
from the EDS165. In this type of ‘open’ operation, the clamp-on probe may be
destroyed!
• During the measurement, the clamp-on probe must be held still. The conductors
should be encircled as symmetrically as possible. Make sure that you do not exert any
pressure on the arms of the clamp-on probe.
• An alarm message signals an insulation fault downstream of the sensor.
• Measure along the lead with the EDS165 until you have found the fault location.
• The fault location is found when the test current through the clamp-on probe is at least
5 mA. On this point, see the chapter on SETTINGS AND ADAPTATIONS in the
EDS470 operating manual.
• For operating currents <10 A, measurement is also possible by encircling one conductor
only. Attention: for currents > 10 A, this may produce the effect that the clamp-on
probe can no longer be opened. This danger is particularly present in direct voltage
systems. If this behaviour occurs, under no circumstances use force, since this would
destroy the clamp-on probe. Instead, you must switch off the relevant system.
After this has been done, the clamp-on probe can be opened without
the application of force.
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