What is the classification of transformers and low-voltage wiring for doorbells under Article 725?

Transformers and low-voltage wiring for doorbells are classified as Class 2 circuits under Article 725 of the National Electrical Code (NEC). Class 2 circuits are designed for limited power applications, which provides a degree of safety by reducing the risk of fire and electrical shock.

Class 2 circuits are permitted to have a maximum output of 100 VA, meaning they can safely handle low power requirements commonly associated with doorbells and similar applications. This classification ensures that the wiring maintains a lower voltage level, typically under 60 volts, making it suitable for low-voltage devices like doorbells.

Moreover, Class 2 circuits also have specific installation requirements that differ from higher classifications, such as needing less stringent protection from physical damage. This allows for flexibility in installation while still adhering to safety standards.

Class 3 circuits, on the other hand, permit slightly higher power levels but are generally more suited for different applications, such as signaling systems or remote control circuits that may require more power than doorbells. Special circuits are not a recognized classification under Article 725, thus making Class 2 the appropriate and correct classification for transformers and low-voltage wiring for doorbells.