Preferential trip

1) disconnect non essential circuit from main bus bar in case of failure or overload of main supply

2)Example Air con, Ventilation fan Galley equipment 

3)Prevent main circuit breaker trip, prevent blackout, overloading of generator 

4)Preferential trip circuit consist of electromagnetic coil, arrangement to provide delay to disconnect non essential circuit 

5)Alarm system function as soon overload is detected and trips operating 

6)mechanical linkages, instantaneous operate circuit and complete circuit for preferential trips

7)Deshpot consist of small piston with small orifice which placed inside small cylinder, piston move up against fluid and time delay is governed by orifice in piston 

8)current passes though electromagnetic coil and linkages are kept from contacting using spring arrangement 

9)When current value increase limit, electromagnetic coil pull the linkages up against the spring force and operate the circuit and alarm 

10)current passes through the coil in prefential trip circuit which pull the piston in dashpot arrangement