Phoenix Contact 1022236 A bus bar specifically designed for the TMC 72 system can accommodate two-phase circuit breakers with a pitch of 17.8 mm, supporting up to 56 positions. The bus bar is capable of handling an end feed current rating of 80 A and can handle AC/DC voltages up to 600 V. It is also UL 508 listed for connection of UL 1077 rated circuit breakers.