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Wire and Cable Ampacities

Copper Size AWG or kcmil Aluminum
TW, NM-B, UF (60°C) RHW, THW, THWN, XHHW, USE (75°C) RHH, THHN, THWN- 2, XHHW-2, SE, RHW-2, USE-2 (90°C) TW, NM-B, UF (60°C) RHW, THW, THWN, XHHW, USE (75°C) RHH, THHN, THWN-2, XHHW-2, SE, RHW-2, USE-2 (90°C)
15 15 15 14** - - -
20 20 200 12** 15 15 15
30 30 30 10** 25 25 25
40 50 55 8 30 40 45
55 65 75 6 40 50 60
70 85 95 4 55 65 75
85 100 110 3 65 75 85
95 115 130 2 75 90 100
110 130 150 1 85 100 115
125 150 170 1/0 100 120 135
145 175 195 2/0 115 135 150
165 200 225 3/0 130 155 175
195 230 260 4/0 150 180 205
215 255 290 250 170 205 230
240 285 320 300 190 230 255
260 310 350 350 210 250 280
280 335 380 400 225 270 305
320 380 430 500 260 310 350
355 420 475 600 285 340 385
385 460 520 700 310 375 420
400 475 535 750 320 385 435
410 490 555 800 330 395 450
435 520 585 900 355 425 480
455 545 615 1000 375 445 500

*Ampacity is based upon the National Electrical Code® (NEC®), 2008, Table 310.16. Allowable Ampacities of insulated conductors rated 0 through 2000 Volts, 60°C to 90°C (140°F to 194°F) and not more than three current-carrying conductors in raceway or cable or earth. Based on ambient temperature of 30°C (86°F).

**Small conductor (14-10 AWG) ampacities shown are per National Electrical Code® (NEC®) 240.4(D).

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Single Conductors

Single Conductors
Cerrowire® single conductor types (excluding TFFN) are pulled through conduit for use in branch circuits, feeders, or service entrance conductors as specified in the NEC®. The voltage rating for all Cerrowire® single conductor type is 600V.
THHN Type THHN or THWN – may be used in wet or dry locations at conductor temperatures not to exceed 90°C. If marked MTW it may be used as machine tool wiring at conductor temperatures not to exceed 60°C. AWM marking signifies appliance wiring material at conductor temperatures not to exceed 105°C. Sizes 1/0 and larger is suitable for use in cable trays.
USE Type USE-2, RHH and RHW-2 can be used for underground service entrance, including direct burial. It may be used in wet or dry locations at conductor temperatures not to exceed 90°C.
XHHW-2 Type XHHW-2 may be used in wet or dry locations where conductor temperatures do not exceed 90°C. 
TFFN Type TFFN can be used as fixture wire where conductor temperatures do not exceed 90°C. It may also be used as MTW at conductor temperatures not to exceed 60°C or as AWM at 105°C.
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Multiple Conductors

Multiple Conductors
Cerrowire® multiple conductor cables are recommended for use as specified in the NEC®. The voltage rating for all Cerrowire® single conductor type is 600V.
NM-B Type NM-B is primarily used in residential wiring as branch circuits for outlets, switches, and other loads. NM-B may be used for both exposed and concealed work in dry locations at conductor temperatures not to exceed 90°C. Ampacity limited to 60°C for conductors.
UF-B Type UF-B may be used underground, including direct burial, for supplying power to outside lamp posts, well pumps, workshops, etc. May be used for interior branch circuit wiring in dry, wet, or corrosive locations at conductor temperatures not to exceed 90°C Ampacity limited to 60°C for conductors.
SEU Service Entrance Cable,Type SEU, is typically used in residential buildings to transfer power from the service drop to the panel box. Each phase conductor is type THHN or THWN which is suitable for use where conductor temperatures do not exceed 90°C.
SER Service Entrance Cable, Type SER, is normally used in multi-family residential housing to take power from meter base to panel box in an individual apartment. Each phase conductor is type THHN or THWN for use where conductor temperatures do not exceed 90°C.
Mobile Home Feeder Mobile Home Feeder is used to connect a mobile home to an electrical supply where permanent wiring is required as specified in the NEC®. Each conductor is Type USE-2, RHH and RHW-2 which is suitable for direct burial at conductor temperatures not to exceed 90°C.
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