The COD current sensing relay is used to initiate switching or control functions upon a change in line current. It is equipped with independently adjustable high current and low current circuit closing contacts, and operates similar to a contact closing AC ammeter with inverse time delay.
The COD relay unit is commonly used for capacitor switching applications. When the high current contact closes, capacitors are connected to the power line in order to raise line voltage.
Conversely, when line current drops sufficiently to maintain the low-set COD relay current contact for a preset time, switching is initiated to disconnect capacitors from the power line.