Entes mks 03 din rail mountable phase failure relay entes mks 03 p the entes mks 03 is a din rail mountable phase failure relay which will prevent the overheating of 3 phase motors due to a phase failure the thermic magnetic relay which is an essential element in motor protection is generally too slow to assure start up without tripping due to both its electromechanical structure and the use of high current setting range p p the entes mks 03 has been designed to eliminate this and to ef