Yet another wiring - subpanel Q

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This is 310-16 Paste this to an 80 column wide screen
    Table 310-16. Allowable Ampacities of Insulated Conductors Rated 0 through 2000 Volts, 60 to 90C (140 to 194F) Not More Than Three Current-Carrying Conductors in Raceway or Cable or Earth (Directly Buried), Based on Ambient Temperature of 30C (86F)      Size Temperature Rating of Conductor. See Table 310-13 Size _________________________________________________________________________ 60C 75C 90C 60C 75C 90C (140F) (167F) (194F) (140F) (167F) (194F) _________________________________________________________ TYPES TYPES TYPES TYPES TYPES TYPES TW*, FEPW*, TBS,SA, TW*, RH*,RHW*, TBS, UF* RH*,RHW*, SIS,FEP*, UF* THHW*, SA, SIS, THHW*, FEPB*,MI, THWN*, THHN*, THW*, RHH*, XHHW*, THHW*, THWN*, RHW-2, USE* THW-2, AWG XHHW*, THHN*, THWN-2, AWG kcmil USE*,ZW* THHW*, RHH*, kcmil THW-2, RHW-2, THWN-2, USE-2, USE-2,XHH, XHH, XHHW*, XHHW, XHHW-2, XHHW-2, ZW-2 ZW-2 _____________________________________________________ ALUMINUM OR COPPER-CLAD COPPER ALUMINUM _________________________________________________________________________ 18 .... .... 14 .... .... .... .... 16 .... .... 18 .... .... .... .... 14 20* 20* 25* .... .... .... .... 12 25* 25* 30* 20* 20* 25* 12 10 30 35* 40* 25 30* 35* 10 8 40 50 55 30 40 45 8 _________________________________________________________________________ 6 55 65 75 40 50 60 6 4 70 85 95 55 65 75 4 3 85 100 110 65 75 85 3 2 95 115 130 75 90 100 2 1 110 130 150 85 100 115 1 _________________________________________________________________________ 1/0 125 150 170 100 120 135 1/0 2/0 145 175 195 115 135 150 2/0 3/0 165 200 225 130 155 175 3/0 4/0 195 230 260 150 180 205 4/0 _________________________________________________________________________ 250 215 255 290 170 205 230 250 300 240 285 320 190 230 255 300 350 260 310 350 210 250 280 350 400 280 335 380 225 270 305 400 500 320 380 430 260 310 350 500 _________________________________________________________________________ 600 355 420 475 285 340 385 600 700 385 460 520 310 375 420 700 750 400 475 535 320 385 435 750 800 410 490 555 330 395 450 800 900 435 520 585 355 425 480 900 _________________________________________________________________________ 1000 455 545 615 375 445 500 1000 1250 495 590 665 405 485 545 1250 1500 520 625 705 435 520 585 1500 1750 545 650 735 455 545 615 1750 2000 560 665 750 470 560 630 2000 ___________________________________________________________________ CORRECTION FACTORS _________________________________________________________________________ For ambient temperatures other than 30C (86F), multiply Ambient the allowable ampacities shown above by the appropriate Ambient Temp C factor shown below. Temp F _________________________________________________________________________ 21-25 1.08 1.05 1.04 1.08 1.05 1.04 70-77 26-30 1.00 1.00 1.00 1.00 1.00 1.00 78-86 31-35 .91 .94 .96 .91 .94 .96 87-95 36-40 .82 .88 .91 .82 .88 .91 96-104 41-45 .71 .82 .87 .71 .82 .87 105-113 46-50 .58 .75 .82 .58 .75 .82 114-122 51-55 .41 .67 .76 .41 .67 .76 123-131 56-60 .... .58 .71 .... .58 .71 132-140 61-70 .... .33 .58 .... .33 .58 141-158 71-80 .... .... .41 .... .... .41 159-176
     *Unless otherwise specifically permitted elsewhere in this Code, the overcurrent protection for conductor types marked with an asterisk (*) shall not exceed 15 amperes for No. 14, 20 amperes for No. 12, and 30 amperes for No. 10 copper; or 15 amperes for No. 12 and 25 amperes for No. 10 aluminum and copper-clad aluminum after any correction factors for ambient temperature and number of conductors have been applied.
Copyright 1995, NFPA
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PS use a fixed width font, like courier 10
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Also, change to fixed width font (Courier New is good).

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On Thu, 26 Feb 2004 04:13:55 +0000, Greg wrote:

It does, NEC 310-16 through 310-19
--
-Doug


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310.16 is the one you use for virtually all building wiring. The 75c column can only be used if the wire is 75c rated and the terminals are also 75c rated. The 90c column is only used for derating purposes. Romex must be used with the 60c column and there is a footnote that limits "small" sizes of any conductor type. That is #14 (15a) #12 (20a) and #10 (30a) unless otherwise permitted.
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Absoluely correct. In the above scenario with 60' of #8 @ 60a you may only be dropping 2.2% of a 240v load but that is still 330 watts in 60'. That is about the same as a string of rope light except you get no benefit from the heat. You might even be compromizing the insulation of the wire.
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