The 3RB1253-0FG30: The relay offers adjustable trip class from 5 to 30, which means you can set it for standard motor start (Class 10) or slower acceleration profiles (Class 20/30) without swapping the unit. It includes integral ground fault detection and a separate overload warning output — both monostable, so they drop out on fault and stay dropped until reset. Control voltage is AC 110-120 V, 50/60 Hz. The main circuit connects via busbar; the auxiliary circuit uses screw terminals. Reset options are manual, automatic, or remote — useful if the relay is mounted in a hard-to-reach spot in the MCC.
No official successor is listed, so a direct drop-in replacement from the same family would need to be verified against your existing mounting and wiring.
Deployment context
This relay mounts in a Size S6 contactor assembly or individually on a busbar system. It's designed for motor control centers (MCCs) and industrial panels where the main circuit is bus-fed and the auxiliary wiring terminates at screw terminals.