Genesis Specialty Cables
Class 1, Class 2 and Class 3 remote control, signalling and power limited circuits that are not an integral part of a device or appliance.
The scope of this article covers: burgler alarm, access control, sound, nurse call, intercom circuits, some computer network systems, some control circuits for lighting dimmer systems, and some low voltage control circuits that originate from listed computer equipment.
NEC DEFINITIONS FOR ARTICLE 725
Class 1 Circuit: The portion of the wiring system between the load side of the overcurrent device or power-limited supply and the connected equipment. The voltage and power limitations of the source are in accordance with NEC Section 725-21.
Class 2 Circuit: The portion of the wiring system between the load side of a Class 2 power source and the connected equipment. Due to its power limitation, a Class 2 circuit considers safety from a fire initiation standpoint and provides acceptable protection from electric shock.
Class 3 Circuit: The portion of the wiring system between the load side of a Class 3 power source and the connected equipment. Due to its power limitations, a Class 3 circuit considers safety from a fire initiation standpoint. Since higher levels of voltage and current than Class 2 are permitted, additional safeguards are specifed to provide protection from an electric shock hazard that could be encountered.
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