ser cable

[Mike Honcho]

good morning all,

i am reconsidering my subpanel project, and had a question. can i run ser through a wall like nm? my house is attached via breezeway to the garage, and it would be cheaper to run ser through the basement and through the connecting wall. (shorter run, no thwn needed). is there any issues with my thinking? thanks


chris

 

[Aceman]

You have it right, you treat it just like Romex. If it's a shorter easier run, go for it!

 

[pattenp]

One caveat. The install methods for SER are the same as NM except for the temperature differences. NM is required to be sized by 60 deg C. SER can sized by 75 deg C if not run within insulation. If the SER is run within insulation then it's sized by 60 deg C.

 

[Mike Honcho]

One caveat. The install methods for SER are the same as NM except for the temperature differences. NM is required to be sized by 60 deg C. SER can sized by 75 deg C if not run within insulation. If the SER is run within insulation then it's sized by 60 deg C.

does this mean if any of it is run within insulation? or only if the whole run is? at 60 deg, 2-2-2-4 would be good to 75amps, correct?

 

[pattenp]

As long as the length of the cable that's run within insulation does not exceed 10% of the total length it's okay to size at 75 deg C. So if your SER is 30ft then 3ft can be within insulation, 40ft is 4ft, and so on, up to a max of 10ft. (Ref NEC 310.15(A)(2) Exception)

 

[Mike Honcho]

i will be over 10 feet in insulation, so i will be maxed at 75. i only planned for 60 amp sub as it was, so i am still in good shape. thanks for all the help.


chris

 

[pattenp]

Yep, 75A is the max for #2 SER at 60 deg C., so you're good to go feeding it off a 60A breaker.

i will be over 10 feet in insulation, so i will be maxed at 75. i only planned for 60 amp sub as it was, so i am still in good shape. thanks for all the help.


chris

 

[Mike Honcho]

one more thing, is it safe to sleeve it in some spots in conduit if neccesary for, protection?

 

[Aceman]

Yes, you can sleeve it.