Busbar Feeder Three-phase busbar systems provide an easy, time-saving and clearly arranged means of feeding 3RV2 motor starter protectors with screw terminals. The system can be used with various types of motor starter protectors up to 32 A. The 3RV19 15 three-phase busbar systems are generally unsuitable for the 3RV21 motor starter protectors for motor protection with overload relay function and for the 3RV27 and 3RV28 circuit breakers according to UL 489/CSA C22.2 No.5-02. The busbars are suitable for between 2 and 5 motor starter protectors/circuit breakers. However, any kind of extension is possible by clamping the connection tags of an additional busbar (rotated by 180°) underneath the terminals of the respective last motor starter protector. A combination of motor starter protectors of different sizes is possible. The motor starter protectors are supplied by appropriate feeder terminals.