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10-05-2009, 05:13 PM
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#21
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B4T Scotchkote installer
Join Date: Feb 2009
Location: Long Island, N.Y.
Posts: 4,455
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Quote:
Originally Posted by GEORGE D
what about 334.80?
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334.80 tells you to use 60 degree column on 310.15
Only problem is there is no chart titled 310.15 
I asked the Forum Historian (Ken.. AKA TOOL) and he directed me to 310.16
Could it be the CMP screwed up and gave us wrong information 
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10-05-2009, 05:54 PM
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#22
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Junior Member
Join Date: Jun 2009
Location: Washington
Posts: 14
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The 90 degree column is for bundling only. You won't find any terminals rated higher than 75 degrees so you can't put anything bigger than an 90 amp breaker in with 4-3.
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10-05-2009, 05:55 PM
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#23
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Not Peter D
Join Date: Jan 2009
Location: USA
Posts: 5,406
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Romex is totally dangerous and should be permanently banned as a wiring method.
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10-05-2009, 06:06 PM
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#24
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Unlimited Lic.Electrician
Join Date: Sep 2008
Location: Charlotte N.C.
Posts: 7,768
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Quote:
Originally Posted by Peter D
Romex is totally dangerous and should be permanently banned as a wiring method.
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Wait a minute romex is your bread and butter right? 
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10-05-2009, 06:17 PM
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#25
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child please.....
Join Date: Oct 2008
Location: Hack City, USA aka New Orleans
Posts: 2,955
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Quote:
Originally Posted by chris856
The 90 degree column is for bundling only. You won't find any terminals rated higher than 75 degrees so you can't put anything bigger than an 90 amp breaker in with 4-3.
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Where are you getting 90 amps?....Its either the 60 degree chart or 310.15b6. I think it is ok to use 4-3nm under the 310.15b6 chart(it is accepted here). Yes, I know they are not thhn, i've heard people say that it was.
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10-05-2009, 06:19 PM
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#26
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B4T Scotchkote installer
Join Date: Feb 2009
Location: Long Island, N.Y.
Posts: 4,455
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I read it as 70 amp breaker max for 4/3 NM
THAT really sucks!!!! 
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10-05-2009, 06:32 PM
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#27
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Seen your member
Join Date: Sep 2007
Location: Cornpatch USA
Posts: 9,988
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Quote:
Originally Posted by william1978
Wait a minute romex is your bread and butter right? |
Peter deosn't use romex, he uses SO and lamp cord. 
__________________
This message is hidden because Forgery, Honda Racer, JackBoot, LawnGuyLandSparky, milehiwire and user 5941 are on your ignore list.
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10-05-2009, 06:33 PM
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#28
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Not Peter D
Join Date: Jan 2009
Location: USA
Posts: 5,406
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Quote:
Originally Posted by 480sparky
Peter deosn't use romex, he uses SO and lamp cord. |
I stopped using that too. I now use telephone wire and Cat 5 for everything.
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10-05-2009, 06:35 PM
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#29
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B4T Scotchkote installer
Join Date: Feb 2009
Location: Long Island, N.Y.
Posts: 4,455
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Anyone hear of a "ser" cable that is like NM, but service entrance rated and would allow #4 to be put on 100 amp breaker
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10-05-2009, 06:57 PM
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#30
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child please.....
Join Date: Oct 2008
Location: Hack City, USA aka New Orleans
Posts: 2,955
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Quote:
Originally Posted by Black4Truck
Anyone hear of a "ser" cable that is like NM, but service entrance rated and would allow #4 to be put on 100 amp breaker
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I thought you use ser and seu on the 60 degree column as well. I think nm or ser is ok to use as a feeder.
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10-05-2009, 07:02 PM
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#31
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B4T Scotchkote installer
Join Date: Feb 2009
Location: Long Island, N.Y.
Posts: 4,455
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Quote:
Originally Posted by NolaTigaBait
I thought you use ser and seu on the 60 degree column as well. I think nm or ser is ok to use as a feeder.
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#4 SE works for 100 amp, but the 4/wire cable is the problem for sub panels
Why I was interested in the "SER" rated cable
Table 310.15(B)(6) Conductor Types and Sizes for
120/240-Volt, 3-Wire, Single-Phase Dwelling Services and
Feeders. Conductor Types RHH, RHW, RHW-2, THHN,
THHW, THW, THW-2, THWN, THWN-2, XHHW, XHHW-2, SE, USE, USE-2
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10-05-2009, 07:08 PM
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#32
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child please.....
Join Date: Oct 2008
Location: Hack City, USA aka New Orleans
Posts: 2,955
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I would think that SER would fall into that category.
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10-05-2009, 07:10 PM
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#33
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Professional Nit Picker
Join Date: Mar 2007
Location: Maryland
Posts: 651
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Quote:
Originally Posted by 480sparky
There's no reference to ampacity for NM in the 60's. The word 'ampacity' wasn't used in the NM Section until 336-26 of the 1999.
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The word ampacity is used in the 1987 NEC section 326-26
" conductors shall be rated at 90 degree ( 194 F). The ampacity of types NM and NMC cable shall be that of 60 degree( 140 F) conductors and shall comply with section 310-15."
The 1987 is the oldest NEC I have at home.
(# 6 NM Cable is rated for 55 amp at 60 degree in the '87)
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10-05-2009, 09:35 PM
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#34
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Seen your member
Join Date: Sep 2007
Location: Cornpatch USA
Posts: 9,988
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I guess I was looking for a specific paragraph titled Ampacity.
The language you mention began in the 1975.
__________________
This message is hidden because Forgery, Honda Racer, JackBoot, LawnGuyLandSparky, milehiwire and user 5941 are on your ignore list.
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10-05-2009, 10:44 PM
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#35
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Senior Member
Join Date: Jan 2007
Location: Baltimore, MD, USA
Posts: 3,490
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Quote:
Originally Posted by chris856
The 90 degree column is for bundling only. You won't find any terminals rated higher than 75 degrees so you can't put anything bigger than an 90 amp breaker in with 4-3.
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You can derate from the 90 degree column. However, the final result cannot exceed the 60 degree column. See 334.80.
4-3 CU romex is a 70 amp conductor, regardless if the terminal is rated 75 deg or 60.
__________________
John from Baltimore
"One day at a Time"
All responses based on the '08 NEC
It's not my fault, it's not my problem, I'm not your solution. 
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10-22-2009, 01:22 PM
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#36
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Inspector
Join Date: Oct 2008
Location: The Great Police State of South Jersey
Posts: 94
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Yes, it is permissible.
I presented this question to my first & fourth year h/s electrical class. They agree that 6/3 NM cable used as a feeder can be protected by a 60A breaker provided the calculated load does not exceed 55A's.
Penn-Tech all day!!
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