In locations subject to excessive moisture or corrosive

vapors or gases, supporting members of other materials shall be permitted. Where steel supporting members are used, they shall run straight through the center of the cable assembly and shall not be cabled with the copper strands of any conductor. In addition to conductors used for control and signaling circuits, Types E, EO, ET, ETLB, ETP, and ETT elevator cables shall be permitted to incorporate in the construction one or more No. 20 telephone conductor pairs, one or more coaxial cables, and/or one or more optical fibers. The No. 20 conductor pairs shall be permitted to be covered with suitable shielding for telephone, audio, or higher frequency communication circuits; the coaxial cables consist of a center conductor, insulation, and Table 400-4. Flexible Cords and Cables (See Section 400-4) 70-308 Braid Type Size No. of Nominal Trade Name Insulation on Each Letter AWG Outer Covering Use Conductors Insulation Thickness* Conductor AWG Mils Lamp Cord C 18-10 2 or more Ther- 18-16 30 Cotton None Pendant Dry Not moset or Loca- Hard or Portions. Usage Thermo- 14-10 45 table plastic Elevator E Three Cotton, Elevator Nonhazardous Cable See Outer one Lighting Locations Note 20-16 20 Cotton Flameand 5. Retardant & Control Moisture- See 20-14 2 or Ther- Flexible Resistant, Note More moset 20-16 20 Nylon See Note 3. 9. Jacket Three Cotton, Nonhazardous NATIONAL ELECTRICAL CODE Outer one Locations Flame- Retardant & Moisture- EO Resistant. Elevator See See Note 3. Cable Note 20-14 2 or Ther- 20-16 20 Cotton 5. More moset One Cotton Hazardous and a Elevator (Classified) Neoprene Lighting Locations Jacket and 14 30 See Note 3. Control See Notes 1 through 9. *See Note 8. Table 400-4. (Continued) ET 20-14 2 or More Thermo- 20-16 20 Rayon Three Cotton Nonhazardous See plastic or equivalent, Locations Note 5. Outer one Flame- Retardant & ETLB 14 30 None Moisture- See Resist. Note 5. See Note 3. Elevator Cable ETP Thermo- Rayon Thermoplastic Hazardous See plastic (Classified) Note 5. Locations ETT Thermo- None One Cotton or Hazardous See plastic equivalent (Classified) Note 5. and a Ther- Locations moplastic Jacket Portable G 8-500 2-6 plus Ther- 8-2 60 Oil- Portable, Extra Hard Usage, Power kcmil Grounding moset 1-4/0 80 Resistant and as Permitted in Sec- Cable Conduc- 250 kcmil- 95 Thermoset tions 520-68(a) and 530-12. tor(s) 500 kcmil ARTICLE 400 FLEXIBLE CORDS AND CABLES Heater Cord HPD 18-12 2, 3, or 4 Thermoset Thermoset with Cotton or Portable Dry Not Asbestos None Loca- Hard or All 18-16 15 Rayon Heaters tions Usage Thermoset 14-12 30 Parallel HPN 18-12 2 or 3 Thermo- 18-16 45 None Thermosetting Portable Damp Not Heater See setting 14 80 Loca- Hard Cord Note 6. 12 95 tions Usage See Notes 1 through 9. * See Note 8. 70-309 Table 400-4. (Continued) Braid Type Size No. of Nominal 70-310 Trade Name Insulation on Each Letter AWG Conductors Outer Covering Use Insulation Thickness* Conductor AWG Mils Thermoset 18-16 15 Cotton Portable Extra Jacketed HS 14-12 (Thermoset/ and or Hard Heater Thermoset HSJ Asbestos) Thermoset Portable Usage Cord with Heaters See Asbestos 18-16 30 Note 7. 18-12 or (All Hard All Thermoset) Damp Usage HSJO 2, 3, or 4 Ther- None Cotton Locations See moset 14-12 30 and Oil- Note 7. (Thermoset/ Resistant Asbestos) Extra Hard HSO 14-12 14-12 45 Usage (All Thermoset) Twisted Porta- PD 18-10 2 or more Thermoset 18-16 30 Cotton Cotton or Rayon Pendant Dry Not ble Cord or Ther- 14-10 45 or Locations Hard NATIONAL ELECTRICAL CODE moplastic Portable Usage Hard Service S 18-2 2 or more Thermoset 18-16 30 None Thermoset Pendant Damp Extra Cord See 14-10 45 or Locations Hard Note 4. 8-2 60 Portable Usage Flexible Stage SC 8-250 1 or more Thermoset 8-2 60 Thermoset** Portable, Extra Hard Usage, and Lighting kcmil 1-4/0 80 and as permitted in Articles Power Cable 250 kcmil 95 520 and 530 Flexible Stage SCE 8-250 1 or more Thermo- 8-2 60 Thermoplastic Portable, Extra Hard Usage, and Lighting kcmil plastic 1-4/0 80 Elastomer** and as permitted in Articles Power Cable Elastomer 250 kcmil 95 520 and 530 Flexible Stage SCT 8-250 1 or more Thermo- 8-2 60 Thermoplastic** Portable, Extra Hard Usage, and Lighting kcmil plastic 1-4/0 80 and as permitted in Articles Power Cable 250 kcmil 95 520 and 530 See Notes 1 through 9. * See Note 8. **The required outer covering on some single-conductor cables may be integral with the insulation. Table 400-4. (Continued) Hard SE 18-2 2 or more Thermo- 18-16 30 None Thermoplastic Pendant Damp Extra Service See plastic 14-10 45 Elastomer or Locations Hard Cord Note 4. Elastomer 8-2 60 Portable Usage SEO Oil-Resistant See Thermo- Note 4. plastic Elastomer SEOO Oil-Resistant See Thermo- Note 4. plastic Elastomer Junior Hard SJ Thermoset Thermoset Pendant Damp Hard Service or Locations Usage Cord SJE Thermo- None Portable Thermoplastic plastic Elastomer Elastomer 8-12 30 SJEO Oil-Resistant Thermoplastic ARTICLE 400 FLEXIBLE CORDS AND CABLES Elastomer SJEOO Oil-Resistant Thermoplastic Elastomer SJO 18-10 2,3,4, Thermoset Oil-Resistant or 5 Thermoset See Notes 1 through 9. *See Note 8. 70-311 Table 400-4. (Continued) Braid 70-312 Type Size No. of Nominal Trade Name Insulation on Each Letter AWG Conductors Outer Covering Use Insulation Thickness* Conductor AWG Mils Junior Hard SJOO 18-10 2, 3, 4, Oil- 8-12 30 None Oil-Resistant Pendant Damp Extra Service Cord or 5 Resistant Thermoset or Loca- Hard Ther- Portable tions Usage moset SJT Thermo- Thermoplastic plastic or 10 45 Thermoset SJTO Thermoset Oil-Resistant or Thermoplastic Thermoplastic SJTOO Oil- Oil-Resistant Resistant Thermoplastic Thermo- NATIONAL ELECTRICAL CODE plastic or Thermoset Hard Service so Thermoset 18-16 30 Oil-Resistant Pendant Damp Extra Cord See Thermoset or Loca- Hard Note 4. Portable tions 18-2 2 or more Usage SOO Oil- 14-10 45 Oil-Resistant See Resistant Thermoset Note 4. Thermoset 8-2 60 See Notes 1 through 9. * See Note 8. Table 400-4. (Continued) All Thermoset SP-1 18 18 30 None Thermoset Pendant Damp Not Parallel See Thermoset or Locations Hard Cord Note 6. Portable Usage 18-16 45 SP-2 18-16 2 or 3 See Note 6. SP-3 18-10 Thermoset 18-16 60 None Thermoset Refrigera- Damp Not See 14 80 tors, Locations Hard Note 6. 12 95 Room Air Usage 10 110 Conditioners, and as permitted in Section 422-8(d) All Elastomer SPE-1 18 Thermo- 18 30 None Thermoplastic Pendant Damp Not (Thermo- See plastic Elastomer or Locations Hard plastic) Note 6. Elastomer Portable Usage Parallel 18-16 45 Cord SPE-2 18-16 2 or 3 See Note 6. ARTICLE 400 FLEXIBLE CORDS AND CABLES SPE-3 18-10 18-16 60 None Thermoplastic Refrigera- Damp Not See 14 80 Elastomer tors, Locations Hard Note 6. 12 95 Room Air Usage 10 110 Conditioners, and as permitted in Section 422-8(d) All Plastic SPT-1 18 Thermo- 18 30 None Thermoplastic Pendant Damp Not Parallel See plastic or Locations Hard Cord Note 6. Portable Usage 70-313 See Notes 1 through 9. * See Note 8. Table 400-4. (Continued) Nominal Braid 70-314 Type Size No. of Trade Name Insulation Insulation on Each Outer Covering Use Letter AWG Conductors Thickness* Conductor AWG Mils All Plastic SPT-2 18-16 2 or 3 Thermoplastic 18-16 45 None Thermoplastic Pendant or Damp Not Parallel Cord See Portable Locations Hard Note 6. Usage SPT-3 18-10 Thermoplastic 18-16 60 None Thermoplastic Refrigera- Damp Not See 14 80 tors, Room Locations Hard Note 6. 12 95 Air Condi- Usage 10 110 tioners, and as permitted in Section 422-8(d) Range, SRD 10-4 3 or 4 Thermoset None Thermoset Portable Damp Ranges, Dryer Locations Dryers Cable 10-4 45 SRDE 10-4 3 or 4 Thermoplastic None Thermoplastic Portable Damp Ranges, NATIONAL ELECTRICAL CODE Elastomer Elastomer Locations Dryers SRDT 10-4 3 or 4 Thermoplastic None Thermoplastic Portable Damp Ranges, Locations Dryers Hard Service ST Thermo- 18-16 30 Thermoplastic Pendant Extra Cord See plastic or 14-10 45 None or Damp Hard Note 4. 18-2 2 or more Thermoset 8-2 60 Portable Locations Usage STO Oil-Resistant See Thermoplastic Note 4. STOO Oil-Resistant See Thermo- Note 4. plastic or Thermoset See Notes 1 through 9. * See Note 8. Table 400-4. (Continued) Vacuum SV 18-17 2 or 3 Thermoset 18-17 15 None Thermoset Pendant Damp Not Cleaner See or Locations Hard Cord Note 6. Portable Usage SVE Thermo- Thermoplastic See plastic Elastomer Note 6. Elastomer Oil-Resistant SVEO Thermo- See plastic Note 6. Elastomer SVEOO Oil-Resistant See Thermo- Note 6. plastic Elastomer SVO Thermoset Oil-Resistant Thermoset SVOO Oil-Resistant Oil-Resistant Thermoset Thermoset SVT Thermoset Thermoplastic See or Thermo- Note 6. plastic ARTICLE 400 FLEXIBLE CORDS AND CABLES SVTO Thermoset Oil-Resistant See or Thermo- Thermo- Note 6. plastic plastic SVTOO Oil-Resistant Oil-Resistant Thermo- Thermoplastic or plastic Thermoset Parallel TPT 27 2 Thermo- 27 30 None Thermoplastic Attached Damp Not Tinsel See plastic to an Locations Hard Cord Note 2. Appliance Usage 70-315 See Notes 1 through 9. * See Note 8. Table 400-4. (Continued) Nominal Braid 70-316 Type Size No. of Trade Name Insulation Insulation on Each Outer Covering Use Letter AWG Conductors Thickness* Conductor AWG Mils TS Attached Not See to an Hard 27 2 Thermoset None Thermoset Note 2. Appli- Damp Usage Jacketed ance Locations Tinsel 27 15 Cord TST Thermo- Thermoplastic Attached Not See 27 plastic to an Hard 2 None Note 2. Appli- Damp Usage ance Locations Portable W 8-500 1-6 Thermoset 8-2 60 Oil-Resistant Portable, Extra Hard Usage, and Power kcmil 1-4/0 = 80 Thermoset as Permitted in Sections 520-68 Cable 250 kcmil 95 and 530-12. 500 kcmil See Notes 1 through 9. * See Note 8. NATIONAL ELECTRICAL CODE ARTICLE 400 - FLEXIBLE CORDS AND CABLES 70-317 shield for use in video or other radio frequency communication circuits. The optical fiber shall be suitably covered with flame-retardant thermoplastic. The insulation of the conductors shall be rubber or thermoplastic of thickness not less than specified for the other conductors of the particular type of cable. Metallic shields shall have their own protective covering. Where used, these components shall be permitted to be incorporated in any layer of the cable assembly but shall not run straight through the center. 6. The third conductor in these cables shall be used for equipment grounding purposes only. 7. The individual conductors of all cords, except those of heatresistant cords, shall have a thermoset or thermoplastic insulation, except that the grounding conductor where used shall be in accordance with Section 400-23(b). Unvulcanized rubber compounds shall be permitted to be used for all sizes of heater cord Types HSJ and HSJO, and for sizes No. 18 and 16 Type HPD. 8. Where the voltage between any two conductors exceeds 300, but does not exceed 600, flexible cord of Nos. 10 and smaller shall have thermoset or thermoplastic insulation on the individual conductors at least 45 mils in thickness, unless Type S, SE, SEO, SEOO, SO, SOO, ST, STO, or STOO cord is used. 9. Insulations and outer coverings that meet the requirements as flameretardant, limited-smoke, and are so listed, shall be permitted to be designated limited-smoke with the suffix /LS after the Code type designation. 400-5. Ampacities for Flexible Cords and Cables. Table 400-5(A) provides the allowable ampacities and Table 400-5(B) provides the ampacities for flexible cords and cables with not more than three current-carrying conductors. If the number of current-carrying conductors exceeds three, the allowable ampacity or the ampacity of each conductor shall be reduced from the 3-conductor rating as shown in the following table: Percent of Value Number of in Tables 400-5(A) Conductors and 400-5(B) 4 through 6 80 7 through 9 70 10 through 20 50 21 through 30 45 31 through 40 40 41 and above 35 Ultimate Insulation Temperature. In no case shall conductors be associated together in uch a way with respect to the kind of circuit, the wiring method used, or the number of conductors such that the limiting temperature of the conductors is exceeded. 70-318 NATIONAL ELECTRICAL CODE A neutral conductor that carries only the unbalanced current from other conductors of the same circuit need not be considered as a currentcarrying conductor. In a 3-wire circuit consisting of two phase wires and the neutral of a 4-wire, 3-phase wye-connected system, a common conductor carries approximately the same current as the other conductors and shall be considered a current-carrying conductor. On a 4-wire, 3-phase wye circuit where the major portion of the load consists of nonlinear loads such as electric-discharge lighting, electronic computer/data processing, or similar equipment, there are harmonic currents present in the neutral conductor, and the neutral shall be considered to be a current-carrying conductor. An equipment grounding conductor shall not be considered a currentcarrying conductor. Where a single conductor is used for both equipment grounding and to carry unbalanced current from other conductors, as provided for in Section 250-60 for electric ranges and electric clothes dryers, it shall not be considered as a current-carrying conductor. Exception: For other loading conditions, adjustment factors shall be permitted to be calculated under Section 310-15(b). (FPN): See Appendix B, Table B-310-11 for adjustment factors for more than three current-carrying conductors in a raceway or cable with load diversity. 400-6. Markings. (a) Standard Markings. Flexible cords and cables shall be marked by means of a printed tag attached to the coil reel or carton. The tag shall contain the information required in Section 310-11(a). Types S, SC, SCE, SCT, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, SJO, SJT, SJTO, SJTOO, SO, SOO, ST, STO, and STOO flexible cords and G and W flexible cables shall be durably marked on the surface at intervals not exceeding 24 inches (610 mm) with the type designation, size, and number of conductors. (b) Optional Markings. Flexible cords and cable types listed in Table 400-4 shall be permitted to be surface marked to indicate special characteristics of the cable materials. (FPN): Examples of these markings include, but are not limited to, "LS" for limited-smoke and markings such as "sunlight-resistant." 400-7. Uses Permitted. (a) Uses. Flexible cords and cables shall be used only for (1) pendants; (2) wiring of fixtures; (3) connection of portable lamps or appliances; (4) elevator cables; (5) wiring of cranes and hoists; (6) connection of stationary equipment to facilitate their frequent interchange; (7) prevention of the transmission of noise or vibration; (8) appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection; (9) data processing cables as permitted by Section 645-5; (10) connection of moving parts; or (11) temporary wiring as permitted in Sections 305-4(b) and 305-4(c). ARTICLE 400 - FLEXIBLE CORDS AND CABLES 70-319 Table 400-5(A). Allowable Ampacity for Flexible Cords and Cables [Based on Ambient Temperature of 30°C (86°F). See Section 400-13 and Table 400-4.] Size Thermoset Thermoset Types Types Type C, E, EO, PD, S, SJ, SJO, AFS, TS SJOO, so, soo, SP-1, SP-2, AFSJ, AWG SP-3, SRD, SV, svo, SVOO HPD, HPN, Thermo- Thermoplastic HS, plastic Types ET, ETLB, ETT, SE, HSJ, Types SEO, SJE, SJEO, SJT, SJTO, HSJO, TPT, SJTOO, SPE-1, SPE-2, SPE-3, HSO TST SPT-1, SPT-2, SPT-3, ST, SRDE, SRDT, STO. STOO, SVE, SVEO, SVT, SVTO, SVTOO At Bt 27* 0.5 20 5** 7** 18 7 10 10 17 12 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. t 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 currentcarrying. The allowable currents under subheading B apply to 2-conductor cords and other multiconductor cords connected to utilization equpment so that only 2 conductors are current-carrying. (FPN): It is intended that this table be used in conjunction with applicable end-use product standards to ensure selection of the proper size and type. (b) Attachment Plugs. Where used as permitted in subsections (a)(3), (a)(6), and (a)(8) of this section, each flexible cord shall be equipped with an attachment plug and shall be energized from a receptacle outlet. Exception: As permitted in Section 364-8. 400-8. Uses Not Permitted. Unless specifically permitted in Section 400-7, flexible cords and cables shall not be used (1) as a substitute for the I fixed wiring of a structure; (2) where run through holes in walls, ceilings, or floors; (3) where run through doorways, windows, or similar openings; (4) where attached to building surfaces; (5) where concealed behind building walls, ceilings, or floors; or (6) where installed in raceways, except as otherwise permitted in this Code. 70-320 NATIONAL ELECTRICAL CODE Exception: Flexible cord and cable shall be permitted to have one connection to the building surface for a suitable tension take-up device. Length of the cord or cable from the supply termination to the take-up device shall be limited to 6 feet (1.83 m). Table 400-5(B). Ampacity of Cable Types SC, SCE, SCT, G, and W. [Based on Ambient Temperature of 30°C (86°F). See Table 400-4.] Temperature Rating of Cable Size 60°C (140°F) 75°C (167°F) 90°C (194°F) AWG/ kcmil D E F D E F D E F 8 60 55 48 70 65 57 80 74 65 6 80 72 63 95 88 77 105 99 87 4 105 96 84 125 115 101 140 130 114 3 120 113 99 145 135 118 165 152 133 2 140 128 112 170 152 133 190 174 152 1 165 150 131 195 178 156 220 202 177 1/0 195 173 151 230 207 181 260 234 205 2/0 225 199 174 265 238 208 300 271 237 3/0 260 230 201 310 275 241 350 313 274 4/0 300 265 232 360 317 277 405 361 316 250 340 296 259 405 354 310 455 402 352 300 375 330 289 445 395 346 505 449 393 350 420 363 318 505 435 381 570 495 433 400 455 392 343 545 469 410 615 535 468 500 515 448 392 620 537 470 700 613 536 The ampacities under subheading D are permitted for single-conductor Types SC, SCE, SCT, and W cable only where the individual conductors are not installed in raceways and are not in physical contact with each other except in lengths not to exceed 24 inches (610 mm) where passing through the wall of an enclosure. The ampacities under subheading E apply to 2-conductor cables and other multiconductor cables connected to utilization equipment so that only 2 conductors are current-carrying. The ampacities under subheading F apply to 3-conductor cables and other multiconductor cables connected to utilization equipment so that only 3 conductors are current-carrying. 400-9. Splices. Flexible cord shall be used only in continuous lengths without splice or tap when initially installed in applications permitted by