Earth Fault and Short Circuit Indicator type EKL 3.2

The reading instrument is incorporated in a plastic housing together with the electronics for the time reset and the evaluating electronics.
Earth faults are indicated with a blinking LED. Short circuits are indicated with one blinking LED per cable.
The fault is remote indicated via one relay (1x changer) for earth fault- and short circuit indication.
The reading instrument is equipped with a test/reset button.
Each sensor consists of a plastic housing, which contains a coil to detect impulses caused by a short circuit or earth fault.
Depending on the version, a connection cable is fixed to the sensor, or the sensor is prepared for connection to a light mains. The housing is fully sealed and follows the standards of IP 67.
The light mains are applied for a potential-free data transmission between the short cicuit sensor and the reading instrument through a 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 exceeds the preadjusted threshold level, an impulse is sent to the reading instrument for evaluation. The respective LED is activated and starts to blink.
Minimum impulse adjustment: The reading instrument is equipped with a setting for minimum impulse duration. The impulse picked up 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 are connected to the reading instrument via light mains.
The earth fault sensor is connected to the reading instrument via cable.