Prometheus
Well-known member
- Joined
- May 17, 2006
- Messages
- 104
Hi guys,
I am getting ready to install a sub panel in my attached garage. The panel is going to be on an exterior 2x4 wall that is already insulated. I am considering scabbing 2x4s or 2x3s to the existing studs to create a void in which to run my feeder cable as well as run my romex through that has no insulation. I know on load bearing walls you cannot notch more than 25% of the stud, but since these are just scabs on to the existing structure (and supporting no load) I should be able to notch them further correct? I still plan on using the protector plates even though the feeder line should still be more than 1.25 inches from the surface.
Also, since the feeder cable will be in contact with insulation only on 1 side instead of encased in insulation, do I need to derate the cable to the 60* ampacity or can I still use the 75? I know the NEC says you can run 10% or 10 feet (whichever is less) in insulation and not derate, but I'm not sure what their definition of "in insulation" is. Thanks.
I am getting ready to install a sub panel in my attached garage. The panel is going to be on an exterior 2x4 wall that is already insulated. I am considering scabbing 2x4s or 2x3s to the existing studs to create a void in which to run my feeder cable as well as run my romex through that has no insulation. I know on load bearing walls you cannot notch more than 25% of the stud, but since these are just scabs on to the existing structure (and supporting no load) I should be able to notch them further correct? I still plan on using the protector plates even though the feeder line should still be more than 1.25 inches from the surface.
Also, since the feeder cable will be in contact with insulation only on 1 side instead of encased in insulation, do I need to derate the cable to the 60* ampacity or can I still use the 75? I know the NEC says you can run 10% or 10 feet (whichever is less) in insulation and not derate, but I'm not sure what their definition of "in insulation" is. Thanks.