|
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. $ ]( \0 e2 k: I) D4 G: @4 A
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.
( Q0 w+ Q9 u8 c5 f+ LClass 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 for Class 2 are permitted, additional safeguards are specified to provide protection from an electric shock hazard that could be encountered.
|) b+ g; a& F D* ~725.21 class 1circuit classifications and power source requirements.
# b- t/ Z6 f# Q( W/ fClass 1 circuits shall be classified as either class 1 power-limited circuits where they comply with the power limitations of 725.21(A) or as class 1 remote-control and signaling circuits where they are used for remote control or signaling purposes and comply with the power limitations of 725.21(B).0 K/ C/ V! {% {- @
(A) class 1 power-limited circuits. These circuits shall be supplied from a source that has a rated output of not more than 30 volts and 1000 volt-amperes.; I1 j- a) M$ w5 r
(1) class 1 transformers. Transformers used to supply power-limited class 1 circuits shall comply with article 4508 i- S, q2 T3 g [& Z' z# y$ N; P) C
(2) other class 1 power sources.
, A. e' y& J( w% `; e(B) Cass 1 remote-control and signaling circuits. These circuits shall not exceed 600volts the power output of the source shall not be required to be limited |
|