How to choose a GFCI device and how to install GFCI circuit breakers, receptacles, or portable, stand-alone GFCI protection devices.
This article series GFCI and AFCI protection for buildings.
We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
GFCI Options, Installation & Wiring Instructions
As we introduce also if certain high-risk electrical circuits in your home or building is not already protected by GFCI devices in the electrical panel or at the appropriate electrical receptacles ("wall plugs"), we recommend that you have that protection added.
The high shock risk areas for which GFCIs add significant safety protection are damp or wet locations or locations where a person is likley to be handling an electrical device and be close to a sink, tub, shower or other plumbing or water equipment.
GFCI detects a tiny (about 4 to 5 milliamps) flow of electrical current between the electrical circuit or something plugged-in to a GFCI-protected electrical receptacle) and the circuit "ground" or the earth. On detection of this current flow the GFCI quickly trips (in about a tenth of a second) to turn off the electrical circuit to reduce the chances of a dangerous or even fatal shock.
Typical GFCI-protected locations include bathrooms, garages, kitchens, at outdoor electrical circuits and of course near swimmng pools. That's not the whole list. At GFCI PROTECTION, GFCI CODES we provide a full list of the locations where electrical codes require this protection in new or renovation construction.
Watch out: never plug any life-saving devices into a GFCI electrical receptacle that will lose power during testing. Every receptacle that will lose power when a GFCI trips should be labelled GFCI-Protected.
We also caution against plugging a refrigerator or freezer or other critical cold-storage equipment into a GFCI-protected receptacle (for example downstream from the actual GFCI devicve) as any condition that trips the GFCI can leave the cold storage equipment off without notice.
Some electrical circuits that need to be assured of continuous operation include medical equipment, refrigerators, freezers, and sump pumps.
See also FREEZE-PROOF A BUILDING where we describe GFCI protection on heat tape circuits powering heat tapes for manufactured and mobile homes.
GFCI circuit breaker: Install a GFCI circuit breaker in the electrical panel, replacing the original breaker, to protect an entire circuit, such as a kitchen, garage, or outdoor receptacle circuit
Below is a Siemens 120V single pole ground fault circuit interruptor circuit breaker or GFCI breaker. The company provides a range of GFCI breakers including 1-pole and 2-poles, from 15A to 60A in size.
The company's data sheet for this GFCI breaker series notes that while a load neutral wire is not required on the circuit, the coiled white pigtail wire from the breaker must be connected to the neutral bus in the electrical panel for the GFCI to work.
Other brands and models of GFCI circuit breakers require that
the hot load (circuit hot or black wire)
load neutral (circuit neutral wire) be connected to the GFCI breaker
the third or pigtail wire that is permanently connected to the GFCI breaker is connected to the panel neutral bus.
Watch out: before buying a GFCI circuit breaker be sure that the breaker is the proper one for the brand and model of electrical panel into which it is to be installed.
OK so what are the exact steps in wiring up or installing a GFCI device?
At CIRCUIT BREAKER REPLACEMENT we describe in further detail the steps followed to replace an existing circuit breaker with a GFCI-type (or AFCI-type) circuit breaker in an electrical panel.
GFCI Add-on Space Limitations in Some Electrical Panels
Standard circuit breaker widths, using Siemens as an example are 1" for a 120V breaker and 2" for a 240V breaker. In some electrical panels, such as our electrical panel photo shown just above on this page, you may find both full-width and half-width breakers already installed.
If the electrical panel is full or quite crowded you may find that you need to replace several normal-width circuit breakers with narrow half-width circuit breakers - a procedure called "skinnying-up" in the panel - in order to make room for a full-width GFCI breaker.
Watch out: if you have to change some circuit breakers from full to half-width or "skinny" circuit breakers AND if there are multi-wire shared-neutral circuits originating in the electrical panel, you will need to take care in locating those circuit breaker pairs to assure that each breaker is on a different panel bus connector and phase. Details are at MULTI-WIRE CIRCUITS
GFCI wall receptacle: Install a GFCI electrical receptacle to replace an existing electrical receptacle in a high-risk location such as a bathroom or kitchen etc.
The GFCI receptacle will protect any device plugged in to that receptacle and it will protect all of the electrical receptacles (and devices plugged into them) that are wired "downstream" from the receptacle where the GFCI is placed.
In some buildings bathroom receptacles are wired in series between two or more baths and a GFCI is placed in the first receptacle in that string.
Portable GFCI devices: Use a plug-in or portable GFCI protection device that is connected to a wall receptacle.
Often a portable GFCI device is simply a short extension cord that includes at one end its own GFCI protection. Devices that are then plugged into the GFCI-protection device are themselves protected, as are their users.
We often use a portable GFCI protector in construction projects to run our power tools because we don't count on every building or home where we work to have properly-installed GFCI protection.
Shown above: a Yellowjacket-brand portable GFCI protected extension cord.
GFCI-protected tools, devices, appliances: some devices may include their own built-in GFCI device. Shown below: Toughbuilt TB-S560 universal miter saw stand with its own built-in GFCI protection, sold at Home Depot stores and by other suppliers.
UL 943, Ground-Fault Circuit Interrupters, retrieved 2016/08/08, original source: http://ulstandards.ul.com/standard/?id=943
Excerpt: 1.1 This Standard applies to Class A, single- and three-phase, ground-fault circuit-interrupters intended for protection of personnel, for use only in grounded neutral systems in accordance with the National Electrical Code (NEC), ANSI/NFPA 70, the Canadian Electrical Code, C22.1 (CEC), and Electrical Installations (Use), NOM-001-SEDE. These devices are intended for use on alternating current (AC) circuits of 120 V, 208Y/120 V, 120/240 V, 127 V, or 220Y/127 V, 60 Hz circuits.
Note: In Canada, the text "intended for protection of personnel" is excluded.
NEMA, "Understanding GFCIs, Developed by the NEMA 5PP Personnel Protection Technical Committee" [Power Point Presentation], (2012)retrieved 2016/08/08, original source: https://www.nema.org/Products/Documents/NEMA-GFCI-2012-Field-Representative-Presentation.pdf
Antman, Steve, Roger Nolter, and Danny Liggett. "New rules for ground fault circuit interrupters." In 2011 IEEE IAS Electrical Safety Workshop, pp. 1-4. IEEE, 2011.
El-Sherif, Nehad, Rick Mendler, John Trotte, and Ajay Pathak. "Ground fault protection of personnel in industrial locations using the new UL 943C." In 2014 IEEE Petroleum and Chemical Industry Technical Conference (PCIC), pp. 409-414. IEEE, 2014, retrieved 2016/08/08, original source: http://www.csemag.com/single-article/ul-s-new-gfci-classes/89c8746cdc4a7fd8a3cb93f1d51ba57a.html
LaRocca, Robert L. "Personnel Protection devices for use on appliances." IEEE transactions on industry applications 28, no. 1 (1992): 233-238.
Neitzel, Dennis K., and Timothy L. Gauthier. "Ground fault protection-GFCI or GFPE-there is a difference." In Electrical Safety Workshop (ESW), 2013 IEEE IAS, pp. 207-210. IEEE, 2013.
Smoot, Arnold W. "GFCI---Applications and Alternatives." IEEE Transactions on Industry Applications 1 (1975): 56-61.
Wills, John H., Jan Ehrenwerth, and Dan Rogers. "Electrical injury to a nurse due to conductive fluid in an operating room designated as a dry location." Anesthesia & Analgesia 110, no. 6 (2010): 1647-1649.
Electrical shock injury statistics: www.healthatoz.com - September 2008;
High-tension current generally causes the most serious injuries, although fatal electrocutions may occur with household current (e.g., 110 V in the United States and Canada and 220 V in Europe, Australia, and Asia). Contact with alternating current at 60 cycles per second (the frequency used in most US household and commercial sources of electricity) may cause tetanic skeletal muscle contractions, preventing self-release from the source of the electricity and thereby leading to prolonged exposure. The repetitive frequency of alternating current also increases the likelihood of current flow through the heart during the relative refractory period (the "vulnerable period") of the cardiac cycle. This exposure can precipitate ventricular fibrillation (VF), which is analogous to the R-on-T phenomenon.-- circ.ahajournals.org - September 2008
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
John Cranor is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-747-7747 or by Email: firstname.lastname@example.org
"Frequency of Occurrence and Sources of Rust and Corrosion in Electrical Panels," Daniel Friedman, IEEE HOLM Conference, Philadelphia PA, 1992 - see ELECTRIC PANEL RUST for an online version of this article.
Jim Simmons: Personal communication, J. Simmons to Daniel Friedman, 9/19/2008. Photographs contributed to this website by Jim P. Simmons, Licensed Electrician, 360-705-4225 Mr. Electric, Licensed Master Electrician, Olympia, Washington Contact Jim P. Simmons, Licensed Master Electrician, Mr. Electric, 1320 Dayton Street SE
Olympia, WA 98501, Ph 360-705-4225, Fx 360-705-0130 email@example.com
Kenneth Kruger: Original author of the sidebar on testing VOM DMM condition: Kenneth Kruger, R.A., P.E. AIA ASCE, is an ASHI
Member and ASHI Director in Cambridge, MA. He provided basis for this article penned by DJ Friedman.
"How to Use DMM's Safely," Leonard Ogden, CEE News, 888 Seventh Ave., New York, NY 10106, Dec 1990 p.10.
Dr. Jess Aronstein, consulting engineer, Poughkeepsie NY, 1991 firstname.lastname@example.org
Rex Cauldwell, master electrician and contributor to the Journal of Light ConstructionOn electrical topics
New York State Central Hudson Gas and Electric Company, G&E/1-2/85 consumer safety pamphlet
American Society of Home Inspectors, ASHI Training Manual, Al Alk -[obsolete, and includes unsafe practices-DF]
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Recommended books on electrical inspection, electrical wiring, electrical problem diagnosis, and electrical repair can be found in the Electrical Books section of the InspectAPedia Bookstore. (courtesy of Amazon.com)
"Electrical System Inspection Basics," Richard C. Wolcott, ASHI 8th Annual Education Conference, Boston 1985.
"Simplified Electrical Wiring," Sears, Roebuck and Co., 15705 (F5428) Rev. 4-77 1977 [Lots of sketches of older-type service panels.]
"How to plan and install electric wiring for homes, farms, garages, shops," Montgomery Ward Co., 83-850.
"Simplified Electrical Wiring," Sears, Roebuck and Co., 15705 (F5428) Rev. 4-77 1977 [Lots of sketches of older-type service panels.]
"Home Wiring Inspection," Roswell W. Ard, Rodale's New Shelter, July/August, 1985 p. 35-40.
"Evaluating Wiring in Older Minnesota Homes," Agricultural Extension Service, University of Minnesota, St. Paul, Minnesota 55108.
"Electrical Systems," A Training Manual for Home Inspectors, Alfred L. Alk, American Society of Home Inspectors (ASHI), 1987, available from ASHI. [DF NOTE: I do NOT recommend this obsolete publication, though it was cited in the original Journal article as it contains unsafe inaccuracies]
"Basic Housing Inspection," US DHEW, S352.75 U48, p.144, out of print, but is available in most state libraries.
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
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The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
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