Why is the standard set for 24 Volt DC?
Power over 30 Volts is not considered “safe” when conductors are exposed (without insulation) and must be enclosed in metal jackets, conduits and enclosures. Power less than 24 Volts (i.e. 12 Volt DC systems) can create more significant power losses in the wiring. The selection of 24 Volt DC provides the dual benefits of flexible, modular wiring and safe, efficient power distribution. Also, many digital devices used within commercial interiors today that inherently use DC power – such as occupancy and day lighting sensors – are already based on this voltage.
