Class 2 wiring protection?

[SPierce]

Generally we install a 12-2 low voltage cable from a Class 2 power supply(driver), to feed undercabinet LED tape light, without any circuit protection other than the circuit breaker. The boss asked me to look into whether or not we need overcurrent protection on the load side of the power supply if we use either 16-2 or 18-2 cable. He had heard of some guys using in-line fuses to protect the Class 2 wiring but not sure if they're required. I can't seem to find the answer in Art. 725 and Chapter 9, Tables 11(A) and 11(B) are somewhat confusing because I'm not sure what an 'Inherently Limited Power Source' and a 'Not Inherently Limited Power Source' are. Any help would be appreciated.

 

[petersonra]

class 2 power supplies are generally designed to not allow more than a specific amount of energy to pass into the conductors. therefore those circuits are inherently protected from over current.

take a look at chapter 9 table 11(A) and (B).

 

[mwm1752]

Table 450.3(B) might help you -- petersonra description :thumbsup: class 2 max @ 5 amps 240.4(D) might have useful info for you

 

[kwired]

class 2 power supplies are generally designed to not allow more than a specific amount of energy to pass into the conductors. therefore those circuits are inherently protected from over current.

take a look at chapter 9 table 11(A) and (B).

There are inherently limited and non inherently limited sources in those tables.

If you had a non inherently limited 250 VA source @ 12 volts - that source can put out 20.8 amps at full load rating- that is enough to heat an undersized conductor enough to be a fire hazard if it doesn't have proper overcurrent protection for the conductor ampacity.