What is preferential trips and how it works

• The current passes through the electromagnetic coil and the linkages are kept from contacting using a spring arrangement. As soon as the current value increases the limit, the electromagnetic coil pulls the linkage up against the spring force and operates the instantaneous circuit and the alarm system. The lower linkage completes the circuit for the preferential trip circuit.
• The current passes through the coil in the preferential trip circuit  which pulls the piston in the dashpot arrangement. The movement of this piston is governed by the diameter of the orifice and the time delay made by the same.

           The preferential trip operates at 5, 10 and 15 seconds and the load is removed                                   accordingly. If the overload still persists, then an audible and visual alarm is sounded