BEY16-4 is a connection set used to easily connect the main poles of the Line, Delta and Star AF09 ... AF16, AFC09 ... AFC16 or AFS09 ... AFS16 contactors of a star-delta starter.
The BEY connection set is made up of:
Line contactor / delta contactor: upstream phase-to-phase connection
Delta contactor / star contactor: downstream connection in parallel
Star contactor: star point upstream
Insulated, solid copper bar