hi raymond,

yes, there is such thing!

a phase failure, phase sequence and voltage drop protectio, all in one.

three phses are connected from one side, common, NO and NC contacts on the other side.

if one fase is missing, or, sequence has changed, or, voltage drop below set, relay change position, and alarm goes on. when things go back to normal, it will stop the alarm and restore tention to controls.

hope that helps.

chemi