DescriptionRelays of the OKPh series are supervision devices for monitoring the directional sequence of phases or detecting the loss of one or more voltages in three phase systems. These components are typically used for detecting faults affecting either a power supply or the sequences of individual phases. The supervision relay can identify undervoltages on one of the 3 phases below a fixed threshold, or detect a phase break: this advantageously prevents the risk of three phase motors operating in single phase mode. In addition, monitoring of the correct R-S-T sequence enables permanent supervision of the status of power supplies to three-phase users, and the avoidance of dangerous incorrect connections. These relays are connected directly to the 400Vac three-phase power line. When the system under supervision is operating correctly, the relay contact remains closed.
The OKPh relay detects the direction of rotation using high quality passive electronic components (R and C) which, in combination with the superior reliability of the electromechanical section, allow these relays to perform key roles in the systems in which they are installed.
The ultra-high reliability and long electrical life expectancy of these components allow them to be used in particularly demanding environments such as, for example, electricity generating stations, electrical transformer stations, and industries using continuous production processes.