Avr electronics is engaged mainly in the development and manufacture of energy management products. The company offers a range of protection relays. Micro controller based ckr series over current relays combine both inverse time and independent time relays in one unit. These relays are used for protecting transformers, motors, generators and power lines in energy distribution systems against short circuits and grounding faults. The most important point to achieve the uppermost protection is to apply "selective protection". The main purpose of selective protection is locating and disconnecting the faulty circuit from the network active. The ckr series have the following i/t characteristics according to iec-255 and bs-142, such as: a - normal inverse; b - very inverse; c - extremely inverse; d - long time inverse; e - independent time 1; f - independent time 2; g - independent time 3; and h - independent time 4.
