SER sizing under 2011 NEC...

[chevyx92]

I was trying to find where now you must size SER according to the 60 Degree column? I can't seem to locate it at the moment. I haven't done residential in awhile but I need to size a circuit for a range. Im thinking a 40 amp circuit will do with #6 Alum SER wire. Is a 40 Amp circuit pretty much the standard circuit to run for a range? Do you see any reason why I would need to run larger? Looking at job tomorrow all customer said is they need a circuit ran for a range they're getting next week because they are getting rid of gas range and going electric.

 

[raider1]

Check out 338.10(B)(4)(a). If the SER cable is installed in thermal insulation you must use the 60 degree column.

Chris

 

[infinity]

The proper answer to your question is also dependent on the NEC cycle you're under.

 

[texie]

The proper answer to your question is also dependent on the NEC cycle you're under.

I don't have my 2008 in front of me, but as I recall it was only 60 degree, just like NM. 2011 made it 75 degree, only if no insulation is involved.

 

[infinity]

I don't have my 2008 in front of me, but as I recall it was only 60 degree, just like NM. 2011 made it 75 degree, only if no insulation is involved.

Sounds right. 2005 and earlier, 75? C with or without insulation encapsulation.

 

[KWH]

Is contact with insulation as in lying on treated the same as being underneath.

 

[Dennis Alwon]

Is contact with insulation as in lying on treated the same as being underneath.

Who knows-- that will be an ahj call. IMO, if it is surrounded in insulation then it's 60C.

Point of Info, I believe if the se cable goes thru a hole that is caulked it doesn't matter if the rest of the run is not in insulation it must be rated 60C.

 

[texie]

Who knows-- that will be an ahj call. IMO, if it is surrounded in insulation then it's 60C.

Point of Info, I believe if the se cable goes thru a hole that is caulked it doesn't matter if the rest of the run is not in insulation it must be rated 60C.

I agree. It can always be something that can be challenged by the AHJ. I think it is just easier and safer to just always assume SE to be 60 degree.

 

[infinity]

Who knows-- that will be an ahj call. IMO, if it is surrounded in insulation then it's 60C.

Point of Info, I believe if the se cable goes thru a hole that is caulked it doesn't matter if the rest of the run is not in insulation it must be rated 60C.

What about 310.15(A)(2)Exception? Could you apply the 10' or 10% rule for the condition you've described?

(4) Installation Methods for Branch Circuits and Feeders.
(a) Interior Installations. In addition to the provisions
of this article, Type SE service-entrance cable used for in-
terior wiring shall comply with the installation require-
ments of Part II of Article 334, excluding 334.80.
Where installed in thermal insulation, the ampacity shall
be in accordance with the 60?C (140?F) conductor tempera-
ture rating. The maximum conductor temperature rating
shall be permitted to be used for ampacity adjustment and
correction purposes, if the final derated ampacity does not
exceed that for a 60?C (140?F) rated conductor.

 

[Smart $]

What about 310.15(A)(2)Exception? Could you apply the 10' or 10% rule for the condition you've described?

IMO, yes. There are no restrictions to the 310.15(A)(2) Exception.

 

[Dennis Alwon]

This exception has been argued forever but apparently it is not allowed to be used here. I have heard that under the right conditions the spot where it is caulked overheats and does damage to the cable,

If the caulk was allowed to be exempt by that exception there would hardly ever be a case where the exception wouldn't apply so why even have it in the code.

 

[Dennis Alwon]

This exception has been argued forever but apparently it is not allowed to be used here. I have heard that under the right conditions the spot where it is caulked overheats and does damage to the cable,

If the caulk was allowed to be exempt by that exception there would hardly ever be a case where the exception wouldn't apply so why even have it in the code.

I see that is in the 2011 and I think I agree with you all. I know NC wouldn't allow that in the past. Now if that rule allows se cable then it should allow nm to be exempt however I believe the intent was to remove the 60C rating and not the caulking aspect of 334.80

 

[electricguy61]

40 amp would be kind of small for a range. Around here, standard is 50amp/4wire

 

[Dennis Alwon]

40 amp would be kind of small for a range. Around here, standard is 50amp/4wire

40 amp circuit is pretty standard for a range however there are some larger ones now that do require 50 amps.