MCB with electronic trigger-off
simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. RCD/ELCB/GFCI and relay.


  
  Human interaction (mechanically flipping the latch)
  


Toggle the RCD switch.


  
  Over-load (MCB inherent feature)
  


Built in on the RCD.


  3.Electronically, by using a small trigger voltage. Once this trigger is applied this switch should be mechanically flipped to off position, so that the user should see it is in OFF state.



Use a relay to switch in a resistance to unbalance the RCD/ELCB/GFCI1. 
When R1 and R2 are switched in there will be more current passing through the live pole of the RCD than is returning on the neutral pole. 
On 230 V systems 4.4 k&Omega; will result in 50 mA difference and this should trip a 30 mA RCD. On 120 V systems R2 may be omitted.



  The device is to be used to run a domestic motor (say 1 HP).


You omitted the voltage so we don't know what current this is likely to be so you'll need to work that out.




RCD = residual current device.
ELCB = earth leakage circuit breaker.
GFCI = ground-fault circuit interrupter.


They're all pretty much the same.