The devices reduce assembly costs, the number of components, and panel manufacturing expense. With stop, lead, and lag switches, they use sequence on-simultaneously off operation. The two loads are energized sequentially but remain on together until the stop switch is opened. The devices protect against failure of the stop and lead switches. If both switches fail, the two pump motors are energized simultaneously when the lag switch is closed. An optional low-profile selector switch allows the units to alternate the loads as standard or lock them to one load or the other for service. Two LEDs indicate relay status.