35
TGH1266E -
05/04
Practical Use
•
Connect one of the clamp-on probes to the EDS165
insulation fault evaluator. Switch on the EDS165 and
set the operating mode switch to position I
∆
s
.
•
After the basic menu has appeared on the display of the
EDS165, test whether the correct nominal system
frequency has been set. The factory setting is 50 Hz.
•
Check whether the correct clamp-on probe and/or the correct measuring current
transformer are set in menu 4 (m4). The factory setting is clamp-on probe PSA3052.
•
It is advisable to keep the contact surfaces of the clamp-on probes clean.
•
First, encircle the green-yellow lead between the PGH185 and earth with the clamp-on
probe. If the EDS165 insulation fault evaluator does not react, the insulation fault has
too high an resistance and it cannot be found.
•
For fault location at a central position of the IT system, encircle
all system conductors,
but not the PE conductor,
with the clamp-on probe. The clamp-on probe should not
be used in the immediate vicinity of devices which generate magnetic fields, such as
transformers or throttles, nor in the vicinity of adjacent conductors with high operating
currents.
•
When the clamp-on probe is encircling ‘live’ conductors, it must not be disconnected
from the EDS165. In an ”open” operation of this sort, the clamp-on probe may be
destroyed!
•
Inside the clamp-on probe, you should aim for the maximum possible symmetry of the
conductors. Keep the clamp-on probe still during the measurement! Make sure that
you do not exert any pressure of the clamp-on probe arms.
•
An alarm message on the display of the EDS165 signals an insulation fault downstream
of the clamp-on probe. It is advisable to carry out the fault search with the buzzer
activated.
•
Measure along the conductor with the EDS165 until the fault is found. Penetrate
radially into the sub-distributions as you do this.
•
The fault location is found when the fault current downstream of the clamp-on probe is
at least 5 mA.
•
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 current
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.
0
2
4
6
8
t(s)
