Question about 408.36

[mark32]

Hopefully this won't sound too dumb but 408.36 states that a lighting & appliance panel maybe individually protected by, at most, two main breakers OR the individual ocp can be forgotten if the panel's feeder's ocp is not greater than the rating of the panel. My confusion stems from the term "individually protected". Lets say one were to feed a mlo "sub" panel from a dwellings main panel, then feed a second mlo sub from the first one. Now, in this scenario how many "main" breakers are protecting the second sub?

 

[quogueelectric]

I think it means a tap like one 200a breaker feeding 2-200a mlo panels tapped off the 200a breaker.

 

[RB1]

Mark,

You can wire as many MLO panels from a feeder as you like as long as the panelboard buses are protected at their rated ampacity by the upstream protective device. The allowance of two circuit breakers to protect the panelboard is for split bus panels.

 

[jim dungar]

Hopefully this won't sound too dumb but 408.36 states that a lighting & appliance panel maybe individually protected by, at most, two main breakers OR the individual ocp can be forgotten if the panel's feeder's ocp is not greater than the rating of the panel. My confusion stems from the term "individually protected". Lets say one were to feed a mlo "sub" panel from a dwellings main panel, then feed a second mlo sub from the first one. Now, in this scenario how many "main" breakers are protecting the second sub?

The main device occurs at the service entrance location or at the single breaker feeding any number of down stream panels.

408.36 is in the code to address the multiple main "split-bus" panel that used to be common in residences. These panels often had 4 main devices, Dryer, Range, Lighting, and ???. The lighting main fed a second bus in the same enclosure containing all of the 1-pole branch circuits.

 

[mark32]

Thank you very much for clearing this up. After eight years in the trade I believe I've only worked on one split bus panel, now it makes sense.

Mark