NEC Questions and Answers based on 2020 NEC^® - May 2020

Figure 01

For EC&M Magazine
By Mike Holt, NEC^® Consultant
Here's the follow-up to yesterday's newsletter. This includes the answers to the questions sent, so you can see how you did.

Note: The answers to these questions are based on the 2020 NEC.
Underlined text indicates a change for the 2020 NEC.

Q1. What is the Code required means of identification of neutral terminals in utilization equipment with polarized connections?
A1. 200.9 Means of Identification
In devices or utilization equipment with polarized connections, identification of terminals to which a neutral conductor is to be connected must be substantially white or silver in color. The identification of other terminals must be of a readily distinguishable different color.

Author's Comment:
►It was never the intent of the Code to require that panelboards and switchgear have the neutral conductor termination points be substantially white in color. Neutral conductor termination screws are typically silver in color so the words or silver were added for clarification.

Q2. Where a premises wiring system contains branch circuits from more than one voltage system what is the Code requirement for the identification of conductors?
A2. 210.5 Identification for Branch Circuits
(C) Identification of Phase Conductors. Circuit phase conductors must be identified as follows:

(1) More Than One Voltage Distribution System. Where premises wiring is supplied from more than one nominal voltage system, the phase conductors of branch circuits must be identified by phase or line and by voltage class at all termination, connection, and splice points in accordance with 210.5(C)(1)(a) and (b). Different systems within the premises with the same system voltage class can use the same method of identification. Figure 01

Author's Comment:
►Voltage class should be read as nominal voltage as used here. For example, a premises with two sources of 120/208V nominal such as a separately derived system, can use the same conductor identification scheme (which in this case would typically be black, red, blue, and white) because the voltage class (nominal voltage) is the same.

(a) Means of Identification. Identification of the phase conductors can be by color coding, marking tape, tagging, or other means approved by the authority having jurisdiction.

(b) Posting of Identification. The method of identification must be readily available or permanently posted at each branch‘circuit panelboard, not be handwritten, and be sufficiently durable to withstand the environment involved.

Ex: Where a different voltage system is added to an existing installation, branch-circuit identification is only required for the new voltage system. The existing voltage system distribution equipment must have a label with the words other unidentified systems exist on the premises.

Author's Comment:
►When a premises has more than one voltage system supplying branch circuits, the phase conductors must be identified by phase and system. This can be done by permanently posting an identification legend that describes the method used, such as color‘coded marking tape or color‘coded insulation.
►Although the NEC does not require a specific color code for phase conductors, electricians often use the following color system:

• 120/240V, single-phase”black, red, and white
• 120/208V, three-phase”black, red, blue, and white
• 120/240V, three-phase”black, orange, blue, and white
• 277/480V, three-phase”brown, orange, yellow, and gray; or, brown, purple, yellow, and gray

Author's Comment:
►Whichever color scheme is used, it is important for it to remain consistent wherever terminated or accessible throughout the entire premises, especially when identifying different system voltages and neutrals.

Q3. What is the NEC requirement for dwelling unit bathroom branch circuits serving receptacle outlets?
A3. (3) Bathroom Area Circuit. At least one 20A, 120V branch circuit is required to supply the receptacle outlet(s) in the bathroom(s) as required by 210.52(D), and any countertop and similar work surface receptacle outlets. This bathroom area receptacle circuit is not permitted to supply lighting outlets or receptacle outlets in other rooms [210.11(C)(3)].‚

Ex: A single 20A, 120V branch circuit can supply all the outlets in a single bathroom area, as long as no load fastened in place is rated more than 10A [210.23(A)].

Author's Comment:
►This implies that the additional bathroom branch circuits identified in 210.52 (B)(1) Ex 2 can be installed.

Q4. What is the Code rule for GFCI protection in dwelling unit basements?
A4. 210.8 GFCI Protection
Ground-fault circuit interruption protection, located in a readily accessible location, must be provided in accordance with 210.8(A) through (F).

Author's Comment:
►According to Article 100, a Ground-Fault Circuit Interrupter (GFCI) is a device intended to protect people by de-energizing a circuit when a current imbalance has a value of 6 mA or higher and does not trip when the current to ground is less than 4 mA.

Author's Comment:
►The GFCI circuit breaker provides ground-fault protection starting at the breaker, so the entire circuit has ground-fault protection. A GFCI receptacle provides ground-fault protection for whatever is plugged into it, but also has load-side terminals that provide downstream protection for any other receptacle(s) or device(s) on the circuit.
►According to Article 100, Readily Accessible means capable of being reached quickly without having to climb over or remove obstacles, or resort to the use of portable ladders.

Informational Note 2: See 422.5 for GFCI requirements for specific equipment such as automotive vacuum machines, drinking water coolers, high‘pressure spray washing machines, tire inflation machines provided for public use, and vending machines.

Informational Note 3: See 555.9 for GFCI requirements for boat hoists.

Informational Note 4: Additional GFCI requirements for specific circuits and equipment are contained in Chapters 4, 5, and 6.

For the application of 210.8(A)(7), 210.8(A)(9), 210.8(B)(5), and 210.8(B)(12), the distance is measured as the shortest path an appliance's supply cord will follow without piercing a floor, wall, ceiling, fixed barrier, or passing through a window.

Author's Comment:
►This new language literally serves to require a receptacle in an adjacent room and to have GFCI protection where that receptacle is within 6 ft of a sink. This would be the case in a house with a master suite and a bedroom receptacle outside of the bathroom doorway, but within 6 ft of the sink in the master bath.

(A) Dwelling Units. 125V through 250V receptacles installed in the following dwelling unit locations must be GFCI protected.

(5) Basements. GFCI protection is required for all receptacles located in finished and unfinished areas of a dwelling unit basement [210.8(A)(5)].

Q5. What is the code rule for GFCI protection of outdoor dwelling unit outlets supplied by single-phase circuits rated 150V or less to ground, 50A or less?
A5. (F) Outdoor Dwelling Unit Outlets. GFCI protection is required for all outdoor dwelling unit outlets, other than those for snow-melting equipment covered in 210.8(A)(3) Ex, that are supplied by single-phase branch circuits rated 150V or less to ground, 50A or less [210.8(F)].

Ex: GFCI protection is not required on lighting outlets other than those covered in 210.8(C).

Author's Comment:
►Here is an example of why it is important to understand the terminology used in the Code. This rule overall mentions, outlets, receptacle outlets, but only lighting outlets in the exception, all of which are outlets but take on different characteristics when defined. (See Article 100 Definitions.)