Short circuit current indicator DS-JD-EKL4

Short circuit current indicator designed to detect short circuits and earth faults in medium voltage networks.

It consists of an indicator unit in a housing for panel mounting (the cutout size in the panel is 92.5x45 + 0.6 mm) and four current transformers connected to the measuring inputs of the device using optical fiber (included in the scope of delivery).

If the phase current exceeds the set value for a predetermined time or exceeds the current flowing earlier by a specified number of times (auto-adjustment), the phase with a short circuit is indicated by short flashes of the corresponding LED (event indicator). In addition, a signal is given to the remote indication contact, using the built-in relay.

The use of Short circuit current indicators is a reliable, fast and rational way to identify a malfunction and its further localization. In a ring power system, damaged sections of the line are disconnected from the network as soon as a faulty section is identified. A defective area is considered to be between the last one that worked and the first one that didn’t work. While the maintenance service is repairing the damaged cable, the rest of the equipment is operating normally. Thus, the shutdown time of the entire network is reduced to a minimum. But even in networks with a radial power supply system, a fault indicator will help you quickly find a damaged cable section without commutation of devices of the entire network.

The fault indicators (short circuit to earth and short circuit in the network) conduct a continuous survey of the network status. As soon as the short-circuit current exceeds the detection threshold, an “error” signal will be given. The “error” signal is controlled by the microcontroller in order to avoid false positives caused by transients in the network.

As a rule, the power in the ring system of power supply is produced from two switches. There may also be another disconnector (switch) on the network. To correctly determine the fault indicators should be in each semiring. In the future, when upgrading the system, the number of indicators may be increased.

In the event of a fault, all indicators located in the semiring will operate. But only the indicators located between the switch and the place of damage will give an “error” signal.

It is necessary to turn off the switches in the entire half-ring to prevent further damage to the cable or the apparatus. According to the indications of the indicators, it is possible to calculate the damaged section of the cable. It will be located after the last indicator that issued the “error” signal and before the first failed indicator. After the localization of the accident, you must replace the damaged cable.

By disconnecting the damaged cable, the remaining consumers re-connect to the network. Thus, the time of disconnection of consumers is minimized, and the maintenance service can repair the damaged cable.

Reset of the emergency mode on the indicators can be done manually, as well as in automatic mode after applying voltage to the reconstructed part of the network