60 or 75 rating

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JDB3

Senior Member
SE cable in insulation, states 60 degree column should be used. Wasn't there something if it was used with a 100 amp or larger feeder, then the 75 degree column could be used for its rating? :?
 

iwire

Moderator
Staff member
Location
Massachusetts
SE cable in insulation, states 60 degree column should be used. Wasn't there something if it was used with a 100 amp or larger feeder, then the 75 degree column could be used for its rating? :?

What year NEC is your area using?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
The state has adopted the 2014, as of last September it went into effect. Thanks.

So look at 338.10-- it can be rated 75C. 110,14 is true if you don't know the rating of the lugs etc. But if all is know and all conductors and terminations are 75C then you can use 75C for circuits 100 amps or less.


338.10(B)(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 interior
wiring shall comply with the installation requirements 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 temperature
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 $

Esteemed Member
Location
Ohio
So look at 338.10-- it can be rated 75C. 110,14 is true if you don't know the rating of the lugs etc. But if all is know and all conductors and terminations are 75C then you can use 75C for circuits 100 amps or less.
338.10(B)(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 interior
wiring shall comply with the installation requirements 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 temperature
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
Not where installed in thermal insulation.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Not where installed in thermal insulation.


Yes-- I thought I was explaining that-- I said If all the terminations and wire is rated 75C then it would be okay. The article should tell him weather he has to use 60C


Now the question begs to be ask.. Will the exception in section 310.15(A)(2) come into play

(2) Selection of Ampacity. Where more than one ampacity
applies for a given circuit length, the lowest value shall be
used.


Exception: Where two different ampacities apply to adjacent
portions of a circuit, the higher ampacity shall be
permitted to be used beyond the point of transition, a distance
equal to 3.0 m (10 ft) or 10 percent of the circuit
length figured at the higher ampacity, whichever is less.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Yes-- I thought I was explaining that-- I said If all the terminations and wire is rated 75C then it would be okay. The article should tell him weather he has to use 60C


Now the question begs to be ask.. Will the exception in section 310.15(A)(2) come into play

You can use the exception for SE cable if you can meet all of the conditions required by the exception. Since 334.80 does not apply to interior SE cable you can use the 10'/10% rule.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
You can use the exception for SE cable if you can meet all of the conditions required by the exception. Since 334.80 does not apply to interior SE cable you can use the 10'/10% rule.


Yes, I was asking the OP if this is a way out for him. That was one of the questions I gave the cmp members that were here earlier this month. The said it was definitely useable. The other option is to pull the se cable out of the insulation if possible. Obviously if it runs up the outside wall he is out of luck possibly.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Yes, I was asking the OP if this is a way out for him. That was one of the questions I gave the cmp members that were here earlier this month. The said it was definitely useable. The other option is to pull the se cable out of the insulation if possible. Obviously if it runs up the outside wall he is out of luck possibly.

Maybe it's just me but all these different rules for NM and SE cable just don't make much sense. In insulation, not in insulation, the exception is not applicable, the exception is applicable, 60? C, 75? C. There must be a better way to hash this out. :rant:
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Maybe it's just me but all these different rules for NM and SE cable just don't make much sense. In insulation, not in insulation, the exception is not applicable, the exception is applicable, 60? C, 75? C. There must be a better way to hash this out. :rant:


The se phenomena has been going on for years, as you well know. I am not sure they will ever get it right. If they are not going to allow it at 75C all the time then I am glad the option is there for us to try and avoid insulation.
 

JDB3

Senior Member
The SE cable goes up the outside wall for about 7 feet. The house will have spray foam insulation, which is on the outside walls & between the rafters. Therefore the SE will only be in insulation for approximately the 7 feet. Thanks guys.
 

Smart $

Esteemed Member
Location
Ohio
The SE cable goes up the outside wall for about 7 feet. The house will have spray foam insulation, which is on the outside walls & between the rafters. Therefore the SE will only be in insulation for approximately the 7 feet. Thanks guys.
Hmmm... whether that is considered interior is debatable. Is this a service riser? If not, what is the total run length?
 
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