Well since the '08 code change now requiring us to use the 60 degree column for SE / SE style R cable I have an excess number of #2 SER spools in my shop. Bought them a few years back on a closeout to use primarily for 100 amp residential subpanels. So what are all you resi. guys using now for your 100 amp sub panels? Copper / Romex or 1/0 SER?
SER Cable
- Thread starter moresi
- Start date
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jwjrw
Senior Member
Im keeping the #2 and fusing it at 90amps.
Hendrix
Senior Member
- Location
- New England
I think you may be able to use it again in 2011.
jwjrw
Senior Member
I thought I read the proposal and the exception they changed in 08 to make it illegal was still gone.
jwjrw
Senior Member
what does in insulation mean exactly? In a wall or space with insulation?
I didn't say they made it less controversial :grin:
Where installed in thermal insulation, the ampacity shall be
in accordance with the 60?C (140?F) conductor temperature
rating. The 90?C (194?F) rating shall be permitted to be
used for ampacity adjustment and correction purposes, provided
the final derated ampacity does not exceed that for a
60?C (140?F) rated conductor. [ROP 7-133]in accordance with the 60?C (140?F) conductor temperature
rating. The 90?C (194?F) rating shall be permitted to be
used for ampacity adjustment and correction purposes, provided
the final derated ampacity does not exceed that for a
jwjrw
Senior Member
Yea it would be too easy to say" if ran inside blah you must" blah 60deg column.
Then again if my girlfriend said what she really "meant" then life wouldnt be any fun!
Yea it would be too easy to say" if ran inside blah you must" blah 60deg column.
Then again if my girlfriend said what she really "meant" then life wouldnt be any fun!
In a world with rampant and hideously poor comparisons, that, sir, is a truly superior analogy.
jwjrw
Senior Member
Volta
Senior Member
- Location
- Columbus, Ohio
Assuming aluminum, you're going to need to fuse that 75 amp load and wire no larger than 80 amps.
240.4(B) > 240.6
T310.16
jwjrw
Senior Member
Well when your wrong you are wrong.....I was thinking ampacity at 60 was higher.
Depends on the situation I guess....
- Location
- Logan, Utah
If the calculated load of the "sub-panel" is less than 80 amps, I would still use the #2 SER and just install an 80 amp breaker.
Chris
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
When would 60C be rated higher than 90C? The wire itself is rated for the amperage at 90C or more but the insulation is the weak link. Just look at the difference in #8 wire at 90C in T. 310.16 and then look at the same wire in T. 310.17 for free air. Same size wire can hold alot more amps. The insulation is what breaks down.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Yet if it is SEU cable as service conductors that same wire in insulation can be used for 100 amps, :-? IMO. I know Gus and I disagree on this one.
jwjrw
Senior Member
Once again I didnt express myself well. I was thinking(not looking) that the #2 had an ampacity of 90amps at 60 deg. But its 90amps at
75 deg. I even said I was wrong..... Happens to all of us on here.... some more than others.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I know it was the part that stated it
that made me make my statement.
I wasn't picking just trying to clarify.
jwjrw
Senior Member
Yea I meant depending on the situation I may run pvc, or a bigger wire or fuse it at 80...
Like I said I dont express myself well and you guys do have exerience in areas I have some but not alot of in...
I learn alot and appreciate you questioning me thanks Dennis.
jwjrw
Senior Member
This only applys to feeders correct? (60 deg ser)
But seu(service entrance cables) is the same insulation and ok for 75 deg column?
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