Class 3 circuitry and accessories can be designed to alleviate the problem of excessive voltage drop. Class 2 and 3 systems do not require the same wiring methods as power, light, and Class 1 systems.

Fig. 1. Class 2 circuits are rendered safe by limiting the power supply to 100VA for circuits that operate at 30V or less. Class 2 circuits are rendered safe by limiting the power supply to 100VA for ...