Electrical Association

Ask the Inspector

QUESTION:

When replacing non-grounding receptacles, is it always permissible to use a GFCI device?

ANSWER:

NEC 406.3(D)(3) allows a non-grounding type receptacle to be replaced with a ground-fault circuit-interrupter device.

But don't stop there!

Other NEC requirements apply, and you'll find that ungrounded receptacles supplying power to certain types of equipment cannot simply be replaced with a GFCI.

Section 250.114 details the specific types of cord and plug connected equipment where the exposed non–current-carrying metal parts shall be connected to an equipment grounding conductor.

First, equipment operated in hazardous (classified) locations or where operated at over 150 volts to ground must be connected to an equipment grounding conductor.

The list is divided into residential and other than residential, but regardless of the occupancy, refrigerators, freezers, air conditioners, clothes-washing, clothes-drying and dish-washing machines, sump pumps and electrical aquarium equipment require connection to an equipment grounding conductor.

Hand-held motor-operated tools, stationary and fixed motor-operated tools, light industrial motor-operated tools as well as motor operated hedge clippers, lawn mowers, snow blowers, and wet scrubbers are also on the list and must also be connected to an equipment grounding conductor.

The general exception is for receptacles supplying equipment that is listed and has a distinctively marked approved system of double-insulation.

Compliance with manufacturer's instructions and the product listing is also an issue to consider. When connection to an equipment grounding conductor is required by the listing, it can be enforced by NEC 110.3.

What can be done in this situation? An equipment grounding conductor can be installed!
NEC 250.130(C) permits the equipment grounding conductor of a grounding-type receptacle to be connected to any accessible point on the grounding electrode system, on the grounding electrode conductor or equipment grounding terminal where the branch circuit for the receptacle originates.

Always check the actual Code text (as that is what is enforced) and always check with the AHJ for local ordinances or provisions that may apply.

NOTICE: Answer does not represent a formal interpretation of the National Electrical Code.