Design
The earth fault and short circuit indicator consists of:
3 pcs. short circuit sensors
1 pc. earth fault sensor
1 pc. reading instrument
4 pcs. light mains
The reading
instrument is incorporated in a plastic housing together with the
electronics for the time reset and the evaluating electronics. The
reading instrument is equipped with a test/reset button. The earth
fault or short circuit is indicated:
Type EKL 8000-1: earth fault and short circuit via one LED each.
Type EKL 8000-3: indication of short circuit for each core via three
LED and indication of earth fault
via one LED.
The remote indication of an earth fault and /or short circuit is
performed via one relay ( 1x changer).
The sensors have a terminal for light mains. The housing is fully
sealed and follows the standards of IP 67.
The light mains serve to connect the earth fault and short circuit
sensors with the reading instrument.
The light mains enable a potential-free data transmission of a fault
indication from the high voltage area.
These light cables are made of PMMA and are available up to a length of
15 m.
Function
The sensors detect earth faults
and short circuits inductively. The operating points for earth fault
and short circuit are adjusted with a threshold level electronic. When
the current picked up by the coil exceeds
the preadjusted threshold level, an LED is lighted in the sensor. Via
the light mains, this light impulse is
sent to the reading instrument for evaluation.
At the reading instrument, the fault will then be indicated via LEDs.
Minimum impulse adjustment: The reading instrument is equipped with a
setting for minimum impulse duration. The impulse picked up from the
sensor is evaluated for its duration. If the impulse length is shorter
than the adjusted value for the mininum impulse duration, no fault will
be indicated. If the impulse duration
is longer than the preadjusted duration, an earth fault or short
circuit will be indicated.
This equipment allows the filtering of peak currents caused by switch
currents or similar circumstances. Wrong indications are thus avoided.
With the instrument 4 values for minimum impulse duration can be
adjusted (times follow request of customer).
The reset of the earth fault or short circuit indication can be done
over:
a) automatic time reset: A time element controls the indication and
resets it after a preadjusted time
(4 values between 0.5 h and 40 h are selectable).
b) manual reset with a push-button
c) recovering net voltage (if the reading instrument is supplied from
the monitored net).
Assembling
-Please refer to assembling
instructions delivered with each instrument -
The reading instrument has to be installed outside the high voltage
area. It is possible to install the short circuit sensors on screened
and unscreened cables. The earth fault sensor must be installed around
all three cores to assure that the sum current of all the three cables
is picked up.
The frames of the sensors can be opened for installation.
The short circuit sensors and the earth fault sensors are connected to
the reading instrument via light mains.
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Technical Data
operating current short
circuit: 200 / 400 / 500 / 600 / 800 / 1000 / 1200 A
operating current to earth fault: 10 / 20 / 30 / 40 / 50 / 60 / 80 /
100 A
(other operating currents available by special request) |
| accuracy: |
+/- 10 % |
| temperature range: |
-20°C to +70°C |
| reading instrument: |
reset time delay: 0.5h to 40h
(4 values)
minimum impulse duration:
40 / 60 / 80 / 160 ms (other values by request) |
| power request: |
stand- by mode: 5-10 µA
indication mode: 60 µA
|
| power supply: |
selectable:
- 230 V AC
- 9 V to 110 V DC
- lithium battery |
| remote indication: |
for
earth fault and short circuit
max. 230 V AC / 50W to 150W |
|
| Dimensions |
(
W * H * D ) |
| reading
instrument: |
panel-mounted
instrument
|
96*
48*63 mm
|
sensor:
|
|
short
circuit sensor
earth fault sensor
|
38* 38*26 mm
38* 38*26 mm |
Protection
class
panel-mounted instrument sensors |
|
IP
46
IP 67
|
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