An automatic transfer switch (10) has 'operate', 'test', nad 'isolate' positions (55, 57, 59). A handle selects a position and a positioning mechanism (65) couples the switch (10) and the handle (63) together. The mechanism (65) has first and second pins (67) for applying force to the switch (10). The mechanism (65) has first and second rotary driver devices (69a, 69b) in engagement with the pins (67) thereby providing redundant switch-positioning mechanisms. The switch (10) is combinable with a bypass switch (13) having 'normal', 'auto', and 'emergency' contact positions. A switch interlock linkage (11) between the transfer and bypass switches (10, 13) includes a bypass plate (125) and a transfer plate (71) coupled together by a bar (135). The bypass switch (13) includes a pivot-mounted bypass interlock member (107) obstructing movement of the bypass plate (125) when the bypass switch contacts are in the 'normal' position. The transfer switch (10) includes a pivot-mounted transfer interlock member (111) obstructing movement of the transfer plate (71) when the transfer switch contacts are in the 'emergency' position.