Dear mr,

Please need a information about any instruments for cut off the current line from main HT lines when there is a 2 phase instead of 3 phase because our all the instruments are 3 phase and when there is 2 phase the contacter for the instruments will burn out.

Thanking you,
Raghavendra M R

You need a Phase Monitor Protection Relay.

This device will monitor each phase, and open a control contact if the voltage varies beyond the appropriate tolerance.

Adding a question or seeking more information in a comment is not the best way to ask for more information. Better to Post Reply.

What kind of details do you need? I can give any detail you like, providing you give more detail regarding your situation.

Or you can Google "Phase Monitor Protection Relay", and find a tremendous amount of information, and chose the best product for your circumstance.