My bathroom, inside near door, has a 2-gang box, containing 2 light switches, powering combination ceiling light and fan. This box is fed by hallway lighting circuit, and the work box is not covered by GFCI.

The changes I want to make are:

  • Exchange both switches with a "2 horizontal switch" device, freeing up a gang (example: Leviton 5634-W)
  • Install a USB-ONLY outlet (example: Leviton USB4P)

My question is whether this change is "to code" (NEC)? I am in Northeast USA (NH).

For completeness: My bathroom electrical outlets ARE on a different circuit, in a different work box, and yes that is protected by GFCI.

The question is about adding a USB "outlet" to an area that normally requires all outlets to be GFI. My understanding is what I plan would be OK because these are low-voltage.

  • 2
    Fascinating question! Typically low voltage has different rules, including USB. But on the other hand, the high voltage is "right there". If it wasn't in a bathroom (or kitchen or other GFCI required area) then there would not be any question. So just a comment because hopefully one of the pros has a real answer. In a quick search, I couldn't find any combo. GFCI + USB - probably because the combination is just so unusual - more & more people have the GFCI upstream (breaker or another part of the circuit) that the combo. would be a rare need. – manassehkatz Jan 13 at 23:06

No, Class 2 power outlets (such as USB receptacles) are not required to have GFCI protection

This can be drawn from the fact that the GFCI requirements in NEC 210.8(A) are specifically restricted to 125V, 15 and 20A receptacles:

(A) Dwelling Units. All 125-volt, single-phase, 15- and 20-ampere receptacles installed in the locations specified in 210.8(A)(1) through (10) shall have ground-fault circuit-interrupter protection for personnel.

(1) Bathrooms

and is further justified by the definition of Class 2 circuit in 725.2 already taking shock hazards into account:

Class 2 Circuit. The portion of the wiring system between the load side of a Class 2 power source and the connected equip‐ ment. Due to its power limitations, a Class 2 circuit considers safety from a fire initiation standpoint and provides acceptable protection from electric shock.

(See also the fact that 210.8 is not referenced in NEC 725.3.)

  • Perfect answer; thank you. The interpretation and citations resolve my immediate question, and give me a reference reading point for my curiosity. In addition since this information isn't well-understood among home inspectors, it helps if/when it's time to sell the house. – Crossfit_and_Beer Feb 1 at 13:57

Either install a GFCI breaker for the USB outlet, or install it downstream of another GFCI outlet. Example Wiring

  • 3
    Thanks Marcellus. Can you add a comment why you feel this is required by the NEC (if you are saying so.. that was the core of my question). My understanding is what I am trying to improve, but as I understand -- in a bath, lighting does not go behind GFCI. Or to restate that, only 120V outlets go behind GFCI. If a 5v USB device fails in any manner possible, that device could never trip the GFCI, so it does not seem like there is a benefit. I'm not resisting the advice I want to learn what section of the code requires this. – Crossfit_and_Beer Jan 31 at 5:20
  • Per 210.8(A)(6), GFCI protection is required for all 15A and 20A, 125V receptacles that serve kitchen countertop surfaces in a dwelling unit... Therefore it is not required by code for a 5V (3A) USB. But remember the purpose of GFCI is to protect people from severe electrical shock and most GFCI can since inflow and outflow current differences of just 4mA. – Marcellus Wiggins Feb 1 at 12:47

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