120 1-800-447-2371 www.lutze.com Calculation of the max. ampacity (Based on “NEC 2023 Edition”) Allowable Ampacities of Insulated Conductors Rated 0 Through 2000 Volts, 60°C - 90°C (140°F - 194°F), with Not More Than Three Current Carrying Conductors in Raceway, Cable or Earth (Directly Buried), Based on Ambient Temperature of 30°C (86°F)* (Based on Table 310.16) Temperature Rating of Conductor 60 °C (140 °F) 75 °C (167 °F) 90 °C (194 °F) Copper size AWG or kcmil Types TW, UF Types RHW, THHW, THW, THWN, XHHW, XHWN, USE, ZW Types TBS, SA, SIS, FEP, FEPB, MI, PFA, RHH, RHW-2, THHN, THHW, THW-2, THWN-2, USE-2, XHH, XHHW, XHHW-2, XHWN, XHWN-2, XHHN, Z, ZW-2 18** – – 14 16** – – 18 14** 15 20 25 12** 20 25 30 10** 30 35 40 8 40 50 55 6 55 65 75 4 70 85 95 3 85 100 115 2 95 115 130 1 110 130 145 1/0 125 150 170 2/0 145 175 195 3/0 165 200 225 4/0 195 230 260 250 215 255 290 350 260 310 350 500 320 380 430 750 400 475 535 * Refer to 310.15(B)(1) for the ampacity correction factors where the ambient temperature is other than 30°C (86°F) ** Refer to 240.4(D) for conductor overcurrent protection limitations Correction Factors Ambient temperature (Based on Table 310.15(B)(1)(1) For ambient temperatures other than 30 °C (86 °F), multiply the allowable ampacities shown above by the appropriate factor shown below. Ambient temp. °C 60 °C (140 °F) 75 °C (167 °F) 90 °C (194 °F) 21-25 (70-77 °F) 1.08 1.05 1.04 26-30 (78-86 °F) 1 1 1 31-35 (87-95 °F) 0.91 0.94 0.96 36-40 (96-104 °F) 0.82 0.88 0.91 41-45 (105-113 °F) 0.71 0.82 0.87 46-50 (114-122 °F) 0.58 0.75 0.82 51-55 (123-131 °F) 0.41 0.67 0.76 56-60 (132-140 °F) – 0.58 0.71 61-65 (141-149 °F) – 0.47 0.65 66-70 (150-158 °F) – 0.33 0.58 71-75 (159-167 °F) – – 0.50 76-80 (168-176 °F) – – 0.41 81-85 (177-185 °F) – – 0.29 Number of current carrying conductors (Based on Table 310.15(C)(1)) Adjustment factors for more than three current carrying conductors in raceway or cable. Number of Current-Carrying Conductors Percent of Values in Tables 310.16 Through Table 310.19 as Adjusted for Ambient Temperature if Necessary 1-3 100 4-6 80 7-9 70 10-20 50 21-30 45 31-40 40 40 and more 35 Number of conductors is the total number of conductors in the raceway or cable adjusted in accordance with 310.15 (E) and (F) Example: Application with a LUTZE DRIVEFLEX® XLPE (C) 1 TSP PVC, Shielded with control pair and an ambient temperature of 43 °C and a required ampacity of 34 Ampere. 1. Factor ambient temperature: 0.87 2. Percentage factor current carrying conductors: 80 Note: The given values are reference numbers to calculate the required cable sizes. LUTZE Inc. is not responsible for the conformity of the values provided by the NEC. 55 A x 0.87 x 0.8 = 38 A > 34 A Our recommendation is a AWG8 + 1 TSP AWG14, Item no. A2170804 Ampacity per National Electric Code (USA)
