Master electrical load control system

A system controls power to multiple a.c. lighting loads from both a central location and from individual controls that are located near the loads. The system includes individual wallbox dimmers that include enabling switches, a master control, and isolation means to accept input signals from the master control and to provide output signals to the dimmers. In a preferred embodiment, a dimmer also provides to the master control a signal that indicates the power being provided to the load that the dimmer controls. Preferably the individual controls provide linear slide dimming, in which the power provided to a load is determined by the slider position. The system permits simplified installation and replacement of system components.