Electrical Power Systems Technology

Lighting Systems 341

Figure 13-12. Circuit for controlling a light from three locations: (A) Schematic

diagram, (B) Positions of the four-way switch

Figure 13-13. Pictorial view of the circuit shown in Figure 13-12(A)

Find: the minimum number of branch circuits needed, and the total

power requirement for the lighting units.

Solution for the branch circuits:

1. Find the number of units that should be installed on each branch cir-
   cuit.