• Programmable bus voltages
• Programmable bus frequencies
• Programmable phase angle difference between two buses
• Dead bus Active/Inhibit feature
• History of 5 latest relay closing details
• Self Supervision facility

JNF 060 is used in power systems in order to prevent interconnection of badly synchronized supplies. Synchro check relay is used in series with a breaker closing circuit and automates the operation of synchronizing two buses.

JNF 060 monitors voltage, frequency and phase angle difference of both the buses. If “dead bus” feature is Inhibit and If the voltage, frequency and the phase angle differences are within the pre-set limits, then the N/O contacts of the relay operates indicating synchronization of the buses else the relay does not operate.
If “dead bus” feature is Active and if the status of one of the buses (bus-1) is programmed as “dead bus” and the other (bus-2) is considered normal, Then, the relay operates if the voltage on bus-2 is greater than 80% of the rated voltage and the voltage on bus-1 is lesser than a programmable value (30%-80% of the rated voltage).
Output relay can be operated either in continuous mode or pulse mode. In continuous mode, the relay N/O contacts operate after a programmable delay and will remain in that condition until either a synchro check fails or h/w or power on reset occurs. In the pulse mode, the relay N/O contacts operate for a short while and gets released after a fixed delay of 150msec.