Signal Circuits

[MBRUESCHKE]

Article 725; includes regulations for Class 1. 2, & 3 signal circuits of 30volts and less. Are 120volt signal circuits treated as normal power circuits?

 

[augie47]

Not necessarily. See 725.41 and 725.41(B)

 

[augie47]

Here is one comment:
Often, remote-control and signaling circuits that do not meet the requirements of Class 2 or Class 3 circuits are classed as Class 1 circuits by default. For example, a listed nurse call system may contain a power supply with an output of 500 watts at 24 volts. Because this power supply exceeds the maximum permitted output of a Class 2 power supply and the output terminals are not marked to indicate the equipment as suitable for a Class 2 power supply, the output circuit wiring is classified as Class 1 and subject to all the Class 1 circuit requirements. **

** Credit to NECPlus A publication you might find well worth investigating

 

[MBRUESCHKE]

Thanks a lot it is much appreciated!!!

 

[don_resqcapt19]

Article 725; includes regulations for Class 1. 2, & 3 signal circuits of 30volts and less. Are 120volt signal circuits treated as normal power circuits?

Class 1 circuits can be up to 600 volts. It is just power limited Class 1 circuits that are limited to 30 volts or less.