- posted
19 years ago
What does Class 1,2 and 3 mean in NEC?
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- posted
19 years ago
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 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 limitations, 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 specified to provide protection from an electric shock hazard that could be encountered.
Basically a class 1 is a signalling circuit that can be anywhere from 0-600 volts You treat it like regular power circuits.
Class 2 is what we usually consider "low voltage". A power limited circuit 30v or less
Class 3 is power limited but can be higher than 30v.
Class 2 & 3 can be run with less robust wiring methods than class 1 and power circuits.