masterselectric
Member
Is #2 SER good for 100 Amps?
SER question
- Thread starter masterselectric
- Start date
- Status
- Location
- Massachusetts
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Ser or seu, residence or not, if this is a sub panel does it carry the full load of the service or not.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Welcome tot he forum. 
Can you provide all of the details for this installation? As mentioned there are too many variables to give an accurate answer with the information provided.
Can you provide all of the details for this installation? As mentioned there are too many variables to give an accurate answer with the information provided.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
electricmanscott
Senior Member
- Location
- Boston, MA
Since we're speculating I'll add my 2 cents.
I bet it's a resi sub panel and he got bagged for unsing #2 AL protected at 100 amps.
I bet it's a resi sub panel and he got bagged for unsing #2 AL protected at 100 amps.
- Location
- Massachusetts
I speculate there is a 95.7835% chance Scott is correct.
FrancisDoody
Senior Member
- Location
- Durham, CT
What code cycle is in use? 2005 or 2008. Big difference concerning feeders
- Location
- Massachusetts
What changed?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
The 2008 just clarified what 2005 meant all along.
FrancisDoody
Senior Member
- Location
- Durham, CT
The 2005 code cycle excluded 334.80 for interior installations.(under Article 338.10. B-4a) Now in the 2008 code that sentence was removed. Now you have to take temperatures limitations on conductors. SER 2-2-2-4 on 100 amp breaker feeding a MLO panel acceptable in the 2005 code not so in the 2008.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Article 310.15(B)(6) says nothing about that. The Table specifically allows se cable so if you meet the conditions of that article then you can use T. 310.15(B)(6). Article 334 does not enter into the equation, IMO.
Dennis knows I have to add my 2? worth. :grin:
In this area of the world, the inspectors are of the opinon that 338.10/334.80 are to be taken into account and ampacity adjustments
do preculde #2 AL SE to be used as an interior wiring method on a 100 amp service.
There are, obviously, two schools of thought on the matter.
As far as the change with feeders (non-service), I think most everyone unde the '08 Code applies the 338.10 change.
In this area of the world, the inspectors are of the opinon that 338.10/334.80 are to be taken into account and ampacity adjustments
do preculde #2 AL SE to be used as an interior wiring method on a 100 amp service.
There are, obviously, two schools of thought on the matter.
As far as the change with feeders (non-service), I think most everyone unde the '08 Code applies the 338.10 change.
- Location
- Massachusetts
I know of nothing to support that opinion.
How many hours do you wish to spend on previous threads
Those who support that theory have received opinions from CMP members and NFPA. Those who don't support the opinion very well may have also.
In TN it remains an unsettled enforcement situation.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
electricmanscott
Senior Member
- Location
- Boston, MA
I'm in Gus's camp, today anyway.
FrancisDoody
Senior Member
- Location
- Durham, CT
ECM magazine did a well written article on this very subject. Dig it out for futhur reference.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
310.15(B)(2) tells me what I can do with services and feeders to a dwelling. 338 only comes into play when we are talking about areas not covered by 310.15(B)(2).
Now I totally agree and believe that this was missed by the CMP. I mentioned this a long time ago when we first started using the 2008. I don't see anything in the NEC to support the opposing view.
I would hope that by 2011 this will be cleared up but from what I read so far I don't see.
Here is the problem. T. 310.15(B)(2) states the wires and cables that are allowed. The article gives us the guidelines for the Table. There is nothing that says to look at art. 338 for derating.
This table would be useless if we had to regard every derating that was involved.
Where does it state if we have to derate this table is no longer applicable. Again where does it mention if I run thru an attic that I would have to use correction factors of T.310.16. At what point (temp) would I not be allowed to use SE in this case?
T. 310.15(B)(2) gives no temp. rating but simply states what size wire for what service. If there is a correct factor needed of .96 would I still be allowed to use this Table? How about .94? Tell me when the Table is no longer applicable. You simply can't and as it is worded today you are allowed to use se cable for a feeder without art. 338 being used.
Now I totally agree and believe that this was missed by the CMP. I mentioned this a long time ago when we first started using the 2008. I don't see anything in the NEC to support the opposing view.
I would hope that by 2011 this will be cleared up but from what I read so far I don't see.
Here is the problem. T. 310.15(B)(2) states the wires and cables that are allowed. The article gives us the guidelines for the Table. There is nothing that says to look at art. 338 for derating.
This table would be useless if we had to regard every derating that was involved.
Where does it state if we have to derate this table is no longer applicable. Again where does it mention if I run thru an attic that I would have to use correction factors of T.310.16. At what point (temp) would I not be allowed to use SE in this case?
T. 310.15(B)(2) gives no temp. rating but simply states what size wire for what service. If there is a correct factor needed of .96 would I still be allowed to use this Table? How about .94? Tell me when the Table is no longer applicable. You simply can't and as it is worded today you are allowed to use se cable for a feeder without art. 338 being used.
- Status