ARTICLE 400: Flexible Cords and Cables

NEC Tables 400.5 and 400.5(A)

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Table 400.5 Adjustment Factors for More Than Three Current-Carrying Conductors in a Flexible Cord or Cable

Number of Conductors Percent of Value in Tables 400.5(A) and 400.5(B)
4 - 6 80
7 - 9 70
10 - 20 50
21 - 30 45
31 - 40 40
41 and above 35

Table 400.5(A) Allowable Ampacity for Flexible Cords and Cables [Based on Ambient Temperature of 30°C (86°F). See 400.13.]

Size (AWG) Thermoplastic Types TPT, TST Thermoset Types
C, E, EO, PD, S, SJ, SJO, SJOW, SJOO, SJOOW, SO, SOW, SOO, SOOW, SP-1, SP-2, SP-3, SRD, SV, SVO, SVOO
Types HPD, HPN, HSJ, HSJO, HSJOO
Thermoplastic Types
ET, ETLB, ETP, ETT, SE, SEW, SEO, SEOW, SEOOW, SJE, SJEW, SJEO, SJEOW, SJEOOW, SJT, SJTW, SJTO, SJTOW, SJTOO, SJTOOW, SPE-1, SPE-2, SPE-3, SPT-1, SPT-1W, SPT-2, SPT-2W, SPT-3, ST, SRDE, SRDT, STO, STOW, STOO, STOOW, SVE, SVEO, SVT, SVTO, SVTOO
    A+ B+  
27* 0.5
20 5** ***
18 7 10 10
17 12 13
16 10 13 15
15 17
14 15 18 20
12 20 25 30
10 25 30 35
8 35 40
6 45 55
4 60 70
2 80 95

*Tinsel cord.

**Elevator cables only.

***7 amperes for elevator cables only; 2 amperes for other types.

+The allowable currents under subheading A apply to 3-conductor cords and other multiconductor cords connected to utilization equipment so that only 3 conductors are current carrying. The allowable currents under subheading B apply to 2-conductor cords and other multiconductor cords connected to utilization equipment so that only 2 conductors are current carrying.

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