A connector arrangement connects the contacts of a stack of terminal blocks, including a first conductive bridge extending longitudinally of a given terminal block for selectively connecting together the contacts thereof, and a second laterally-extending conductive bridge for connecting together corresponding contacts of various selected terminal blocks of the stack. The terminal blocks are mounted in parallel vertical orientation on an orthogonally arranged horizontal mounting rail. Vertical branch lines extend upwardly from a plurality of horizontal vertically-spaced bus bar members contained in each of the terminal blocks, and intermediate branch lines connected with the upper ends of the vertical branch lines contain offset tiered first and second contact areas. Resilient fingers on the longitudinal and lateral conductive bridges extend into and electrically engage openings contained in the first and second contact areas, respectively.