Stumped by the Code? NEC Requirements Related to the Installation of Conductors

All questions and answers are based on the 2020 NEC.

Q. What are the Code requirements for electrical connections in marinas, boatyards, and docking facilities?

A. Floating piers [Sec. 555.30(A)] – Electrical connections must be located at least 12 in. above the deck of a floating pier (See Fig. 1).

Fixed piers [Sec. 550.30(B)] – Electrical connections must be located at least 12 in. above the deck of a fixed pier and not below the electrical datum plane.

Replacements [Sec. 550.30(C)] – Replacement electrical connections for a floating pier must be located at least 12 in. above its deck.

Fig. 1. Electrical connections must be located at least 12 in. above the deck of a floating pier. — **Fig. 1.** Electrical connections must be located at least 12 in. above the deck of a floating pier.

Q. What are the NEC rules regarding ground-fault protection of equipment (GFPE) and ground-fault circuit interrupter (GFCI) protection for marinas, boatyards, and docking facilities?

A. For other than floating buildings, ground-fault protection for docking facilities must be provided in accordance with the following [Sec. 555.35(A)]:

(1) GFPE protection. Receptacles installed in accordance with Sec. 555.33(A) can have individual GFPEs set to open at currents not exceeding 30mA.

(2) GFCI protection. All 15A and 20A, 125V receptacles for other than shore power must be protected in accordance with Sec. 555.19(B)(1) and (B)(2).

(3) Feeder and branch-circuit conductors with GFPE. Feeder and branch-circuit conductors that are installed on docking facilities must be provided with GFPEs set to open at currents not exceeding 100mA.

A review of reported electrical shock drowning (ESD) events shows that 50% of the ESD incidents may have been avoided by having the 30mA protection at the shore power receptacles.

Q. What are the general NEC requirements related to the installation of conductors?

A. Single conductors (Fig. 2) must be installed in a Chapter 3 wiring method such as in a raceway, cable, or enclosure [Sec. 300.3(A)].

Fig. 2. Single conductors must be installed in a Chapter 3 wiring method such as in a raceway, cable, or enclosure — **Fig. 2.** Single conductors must be installed in a Chapter 3 wiring method such as in a raceway, cable, or enclosure

Single conductors must be installed in a Chapter 3 wiring method such as in a raceway, cable, or enclosure [Sec. 300.3(A)].

All conductors of a circuit, including the neutral and equipment grounding conductors, must be installed together in the same raceway, cable, trench, cord, or cable tray; except as permitted by (1) through (4) [Sec. 300.3(B)].

(1) Paralleled Installations. Conductors installed in parallel in accordance with Sec. 310.10(G) must have all circuit conductor sets grouped together within the same raceway, cable tray, trench, or cable.

Author’s comment: Grouping of all conductors of the circuit is to minimize heating of surrounding ferrous metal raceways and enclosures by induction for alternating-current circuits. See Sec. 300.20(A).

Connections, taps, or extensions made from paralleled conductors must connect to all conductors of the paralleled set.

Exception: Parallel phase and neutral conductors can be installed in individual underground nonmetallic raceways (Phase A in raceway 1, Phase B in raceway 2, and so forth) as permitted by Sec. 300.5(I) Exception No. 2 if the installation complies with Sec. 300.20(B).

(2) Outside a Raceway or an Enclosure. Equipment bonding jumpers can be located outside of a raceway if the bonding jumper is installed in accordance with Sec. 250.102(E)(2).

For direct-current circuits, the equipment grounding conductor can be run separately from the circuit conductors in accordance with Sec. 250.134(2) Exception No. 2.

These materials are provided to us by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code.