LY16-4 is an insulated connecting strip used on 3-pole AF(C)(S)09..16 contactors:
To obtain a star point (3 parallel-connected poles).
To connect 2 poles (LY16-4 includes secable strips) or 3 poles in parallel and thus increase the AC load passing through the flow path made up of the parallel-connected poles. The relevant cable cross-sectional area may limit the maximum permissible current: consult technical data information on catalogue.
To connect 2 or 3 poles in series and thus increase the DC voltage controlled by the poles: LY16-4 includes secable strips.