• JVS Electronics Private Limited

Numerical Overfluxing Relays

JVS Electronics offers Numerical Overfluxing Relays. Description: JNF 020 calculates the V/F ratio from the measured phase voltage and frequency. When the phase voltage increases or the system frequency decreases the VIF ratio may exceed the set value. If V/F > the set value, then the relay extends a tripping signal. Definite time characteristics dictate the operating time for alarm contact and inverse time characteristics determines the operating time for trip contacts. Features: programmable V/F setting; programmable rated voltage; programmable operating characteristics; trip test facility. RS232 communication port (optional); and history of 5 latest faults. Application: Numerical overfluxing relay, type JNF 020 is used for protection of transformers and generators against insulation failure and core damage due to over heating under prolonged over fluxing conditions. It protects the equipment against abnormal V/F ratios due to system disturbance, which can occur during starting, load shedding and shut down conditions. For larger V/F changes, "the inverse time characteristics enable faster operating time. Technical data: ratings - voltage - 110 V, 50 Hz (it can be programmable from 105 to 120 V in steps of 1 V), frequency - 50 Hz and auxiliary supply - 30 V DC (20 to 60 V DC), 110 V AC/DC (75 to 150 V DC or 60 to 132 V AC) and 220 V AC/DC (150 to 300 V DC or 150 to 250 V AC); burden - AC voltage input - 2 VA rated voltage; and auxiliary supply - less than 4 W (non operated), less than 10 W (operated).