Master electrical load control

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 (26, 28) that include enabling switches, a master control (21), and isolation means (38) 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. Another system of the invention controls electrical power to multiple loads from both a central location and from local three-way controls. In one embodiment, the system includes means for sensing the power to each load. That sensing capability, in turn, permits the master to set all loads to the same power level, simultaneously, regardless of their original level. The local controls may be standard three-way dimmers or switches.