Synchro-Check Relay (Paralleling)   Application :   The Rishabh Paralleling Protector provides manual / automatic switching of generator to busbar without damage or disturbance to the system. The volt-free relay contacts change state when the voltage level, phase relationship and frequency are within the selected synchronising limits.       Principle of Operation :   Model 256-PLL :   The protector monitors voltage values from both busbar and incoming generator systems. The generator supply powers the electronics and the relay. A time delay ensures frequencies are virtually equal at synchronising.   Model 256-PLD :   This model operates in the same way as type 256-PLL, with the addition of the ‘dead bus’ facility. This extra feature enables the relay to energise with a generator supply only. Thus type 256-PLD will allow the generator to power the busbar during mains failure. The relay provides one pair of normally open and one pair of normally closed contacts. An LED indicates relay energised state. The synchronising set point limits are user adjustable.       Features :   • Protection Ensures   • Frequency matching   • Voltage matching   • Phase angle matching         Specifications :   Nominal Voltage 100, 110, 120, 220, 230, 240, 380, 400, 415 & 440V Voltage tolerance -25% to +30% of the nominal voltage Frequency 45 / 65 Hz Burden maximum Bus 2VA, Generator 4VA Set Point : Synchronising 2 Set point 10% to 30% of the nominal voltage Adjustment (6° to 20° electrical) Weight Approximately 0.85kg Output Relay : Contacts 1 pair NO*, 1 pair NC* Rating A.C 240V,5A non-inductive   D.C View chart Operations 0.2 million at the above loads Reset Automatic       *1 pair NO and 1 pair NC available on request Option of 2 pair NO or 2 pair NC available on request.     - Protector Trip Relays   - A.C. Current Relay   - A.C. Voltage Relay with adjustable differential   - A.C. Voltage Relay with adjustable time delay   - Frequency Relay   - Combined Under / Over Voltage & Under / Over Frequency Relay   - Phase Sequence & Phase Failure Relay   - Phase Balance Relay   - Reverse Power (Current) Relay   - Synchro-Check Relay(Paralleling)   - D.C. Voltage Relay   - Thermistor Trip Relay   - Hot Spot 3 Relay   - Hot Spot 6 Relay   - Millivolt / Thermocouple Relay   - Transducer Trip   - Speed Sensing Trip Relay