Three phase induction motor connection with MCCB, contactor and OLR When connecting a three-phase induction motor, commonly used components include a Molded Case Circuit Breaker (MCCB), a contactor, and an Overload Relay (OLR). The overload relay is typically connected in series with one or more phases of the motor. It monitors the motor's current and protects it from overheating due to excessive current draw. The overload relay is usually adjustable, allowing the user to set the desired current