NEC 2020 – 300.6(A)

Electrical equipment shall not be located in wet or damp locations, or where exposed to harmful agents, unless identified for use in such environments.

200-7(b)

NEC 2020 – 200.6(A)

The grounded conductor (commonly referred to as the neutral) must be identified by a continuous white or gray outer finish, or by three continuous white stripes on other than green insulation.

NEC 2020 242.28 (Conductors):

The conductors used to connect the SPD to the line or bus and to ground shall not be smaller than 14 AWG copper or 12 AWG aluminum.

NEC 2020 – Article 100 (Definitions)

Listed: Equipment, materials, or services included in a list published by an organization that is acceptable to the AHJ, concerned with product evaluation, that maintains periodic inspection of production, and whose listing states that the item meets appropriate standards.

NEC 2020 – 300.4(A)(1)

“Where the distance cannot be maintained, the cable shall be protected from penetration by nails or screws by a steel plate(s) or equivalent that is at least 1/16 inch thick.”

725-21(a)

NEC 2020 Reference:

Article 725.43 – Overcurrent Protection (Class 1 Circuits)

"Overcurrent protection shall not exceed 7 amperes for 18 AWG, 10 amperes for 16 AWG, and 15 amperes for 14 AWG conductors, unless specifically permitted in 310.16."

NEC 2020, 800.53(A)

Lightning Conductors. Where practicable, communications wires and cables shall be separated at least 6 ft (1.83 m) from lightning conductors.

NEC 2020 – Table 250.122 and 250.118

The minimum size copper equipment grounding conductor is 14 AWG, and this applies to grounding raceways as well, provided the overcurrent protection is 20 amps or less.

NEC 2020 – Article 110.2

“The conductors and equipment required or permitted by this Code shall be acceptable only if approved.”
"Approved" means acceptable to the AHJ, who has the authority to enforce the Code.

Article 300.19(A), Table 300.19(A) — Supporting Conductors in Vertical Raceways

For No. 16 AWG copper conductors, the maximum support interval in a vertical raceway is:
✅ 135 feet

CH9, TB8

ChatGPT said:

TB 11(a) &11(b)

NEC 2020 Reference:

• 725.127(A) – Overcurrent Protection

• Also supported by UL 1310 and UL 60950 standards for power supplies

645.5(D)(2):

“Cables and receptacles under the raised floor shall be limited to the following: (1) Type DP cable; (2) Type MI, Type MC, or Type AC cables; (3) wiring methods listed in 300.22(C).”

645.5(D)(3):

“Cables shall be installed in accordance with their listing and any applicable installation instructions.”

According to NEC, Article 820.133(A):

Coaxial cables shall not be placed in any enclosure, raceway, cable tray, compartment, outlet box, or junction box with electric light, power, or Class 1 circuit conductors unless separated by a barrier.

Article 300.5(H) — Raceways in Wet Locations Underground

“Where raceway is installed underground and terminates at an underground location, a bushing or terminal fitting shall be used to protect the conductors from abrasion.”

NEC 2020 – 250.20(A) Exception and 250.21(A)

AC systems of less than 50 volts are not required to be grounded where supplied by an isolating source, and where the circuit conductors are isolated from ground and the voltage does not exceed limitations for ungrounded systems.

725-54(a)(1)  EXC 1 & 2

According to NEC 2020, Chapter 9, Table 1, when more than 2 conductors are installed in a conduit (such as Rigid Metal Conduit — RMC), the maximum conduit fill is:

• 40% of the conduit’s total cross-sectional area.

This applies to all types of conduit including EMT, RMC, and others.

Chapter 9, Table 1 – Percent of Cross Section of Conduit and Tubing for Conductors

• More than 2 conductors → 40% maximum fill

645-5(a)

725-51 EXC

NEC 2020 Reference: Article 725.127(B) – Conductor Size Exception

This provision allows:

“The input leads of a transformer or other power supply supplying Class 2 or Class 3 circuits shall be permitted to be smaller than 14 AWG, but not smaller than 18 AWG, if they are not more than 300 mm (12 inches) long and have insulation that complies with 725.27(B).”