How I will be able to design a system which will not effect to our main supply of source when we short two phases of a three phase electrical system.any how is it possible to isolate mains supply with the system phase shorting effect.

What your looking for is a differential relay, AKA protective relay.

Have the wires protected by circuit breaker, use a 20 amp. Stay Isolated(Insulated), short the 2 together. Wear eye protection.

Sorry, thought it was an experiment?

No experiment here, I hope. My guess is a junior engineer in training.