Protection Relay Dealers in Bidadi, Bangalore

Features Suitable for 1A / 5A relay rating Choice of 6 IDMT curve and definite time History of 6 latest faults along with settings Self supervision facility Breaker status monitoring In-built breaker trip circuit supervision Disturbance records (DR) in IEEE COMTRADE format – Optional Event Records (ER) – Optional Programmable digital inputs and outputs MODBUS open protocol over RS – 485 port MODBUS protocol over RS – 232 port Draw out facility with inbuilt CT shorting Principle of Operation: JNC 268 N / JNC 268 A / JNC 268 L : The relay measures the line current from each of the line CTs and if the current exceeds the set threshold, then relay extends a trip signal after an operating time. The relay's “operating time” is determined by selecting “definite time” or one of the six “inverse time” characteristics. A sensitive earth fault or restricted earth fault (suitable for high impedence REF scheme) is provided in the relay.The input to sensitive earth fault protection can be connected in two ways. First one the residual current derived from three phase current transformers, and second is low output core balance current transformer can be connected. The input to restricted earth fault protection will be derived from neutral CT output with external stabilizing resistor.The relay has facility to monitor circuit breaker operation through 52a or 52b aux contacts of circuit breaker. 4 programmable digital inputs (PDI) and 4 programmable digital outputs are provided and can be used to synthesize logic along with some internal digital inputs i.e.(phase OC pickup, Earth fault pickup, Phase high set trip, Earth fault OC trip, Earth fault high set trip,etc). Together, this feature can be effectively used to reduce the number of aux. tripping relays in a protection scheme. The trip relay (B1-B2) can be operated either when any one / more of the protection scheme provided inside JNC 268 x initiates the relay or any/more of the PDI initiates the same relay. Each PDO has independent timer. Each PDI has programmable mask facility.The relay in-built breaker trip circuit supervision and dedicated alarm contact to indicate trip circuit failure. JNC 268 A : Provides Multi shot auto re-closer facilitates automation of breaker operation. Auto re-closer can be programmed to provide a maximum of five shots. “Dead time” starts when a trip signal is provided due to the occurrence of a fault involving L-L or L-G or L-L-G or L-L-L or L-L-L-G. After an elapse of a time interval equal to “dead time”, closing command will be extended. The “reclaim time” timer starts at the instant when the “dead time” timer expires. If after extending the “breaker close” signal an over current fault was detected before the “reclaim time” timer reached its terminal count, then the relay understands that the fault in the system is still persisting and the over current relay will issue a trip signal. The relay tries to close the breaker for a maximum of the programmed number of shots before it choses to lockout. The relay can be configured for independent trip sequence as IDMT or Def. time JNC 268 L : The relay monitors line current even after the trip condition to ensure breaker operation. Even if small current exist in the line the relay sends trip command to adjacent or backup breaker after definite operating time. The current threshold and definite time required to detect breaker failure are programmable.

Features Software based design Block on Start feature provides very accurate overload protection Definite time over load protection Locked rotor current protection Single phasing protection Wide setting ranges Draw -out case