Bender EDS3090, Manual

Page: 22 / 68

Considerations prior to use
22 EDS309x_D00012_03_M_XXEN/11.2014
4.3 Reduced locating current
Particularly in DC control voltage systems in the power station and public utility sector there may be
relays or PLCs installed that switch at relatively low currents. In such a case the I
max
switch on the
PGH18… must be placed in the 10 mA or 1 mA position. The switch's label, e.g. 10 mA or 25 mA, de-
fines the magnitude of the locating current only for DC systems. For AC locating currents see
"chapter 4.4".
It must also be checked prior to a measurement with reduced locating current (switch position 10
mA or 1 mA) whether sensitive system components could be triggered unintentionally.
4.4 Response sensitivity characteristics of the EDS195P
The type of system, system voltage, system frequency, system leakage capacitance and locating cur-
rent all affect the EDS system's response sensitivity. The magnitude of the locating current can be set
on the locating current injector PGH18…. A reduced locating current is produced in AC systems de-
pending on the type of system. In comparison to DC systems the related factor in AC systems is 0.5
and in 3AC systems 0.67. For this reason set the response value on the EDS195P for usage in AC and
3AC systems as follows:
Tab. 4.1: Settings for the EDS195P and the PGH18…
For the response value setting see menu item “2. Settings/ 2. I
Δ
L) on page 39. The response values
are given as characteristics that can have a maximum error of ±30 %. Measuring clamp tolerances are
included here. The characteristics apply at the related nominal voltage stated.
In case of variation in the nominal voltage, a proportional change in the response values is to be ex-
pected. In case of system voltages that change dynamically or in case of superimposed DC currents
and AC currents that vary from the system frequency (e.g. due to frequency converters), response
values outside the ranges shown may result.
Settings Main circuit Control circuit PV system
Equipment for
insulation fault location
EDS3090
EDS3090PG
EDS3090PG-13
EDS3092PG
EDS3096PG
EDS3091
EDS3091PG
EDS3091PG-13
EDS3092PG
EDS3096PV
EDS195P setting:
select the measuring clamp type
using button
PSA 30 20, PSA 30 52,
PSA3165
Measuring range
2…50 mA
PSA 33 20, PSA 33 52
Measuring range
0,2…5 mA
PSA 30 52
Measuring range
2…50 mA
PGH18… setting:
locating current
I
L
25 mA
(PGH185/186)
2,5 mA
(PGH183)
25 mA
(PGH186)
Response range EDS195P
Menu item 2.2: I
Δ
L ALM
2…10 mA 0,2…1 mA 2…10 mA
PGH18… setting:
reduced locating current
I
L
10 mA
(PGH185/186)
1 mA
(PGH183)
10 mA
(PGH186)
Response range EDS195P
with reduced locating current
Menu item 2.2: I
Δ
L ALM
2…5 mA 0,2…0,5 mA 2…5 mA