Safe Electrical Inspection Procedures GFCIs and AFCIs for Home Inspectors
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Safety considerations during the inspection or test of GFCIs - ground fault circuit interrupters
Safety considerations during the inspection or test of AFCIs - arc fault circuit interrupters
Electrical Inspection procedures for the inspection of GFCIs and AFCIs for home inspectors & electrical inspectors
Questions & answers about how to inspect the operating safety & condition of arc fault circuit interrupters and ground fault circuit interrupters
This article discusses safety procedures for the electrical inspector, home inspector, or other professionals while examining GFCIs and AFCIs.
Safe electrical inspection procedures and safe use of
volt meters, DMMs, multimeters, and similar electrical test equipment
is discussed at the end of the article.
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These electrical inspection suggestions are not a complete inventory of all electrical safety procedures nor of all electrical components that should be inspected; these notes focus on identification of conditions that may present special electrical hazards for the electrical inspector.
8.1.F. [The inspector shall observe] the polarity and grounding of
all receptacles within six feet of interior plumbing fixtures, and
all receptacles in the garage or carport, and on the exterior of inspected
structures
Testing is commonly performed using one of a variety of electrical
testers. First perform the visual inspection for overheating, looseness,
arcing as noted above for switches. If a device is quite loose we
do not test further but report it as a required repair. [See "Electrical
Receptacles" in this issue.]
8.1.G. [The inspector shall observe] the operation of Ground Fault
Circuit Interrupters.
While manual operation of these devices using their internal test
button is possible, experience and information about the construction
and operation of these devices and the circuits which they serve suggest
that testing using GFI-test equipment adds additional information
and will find defects not disclosed by manual operation. See
"GFCI's" in the original issue of the ASHI Technical Journal.
Electrical "outlet" receptacle testers like the ones shown in these two photos are used by most home inspectors to check for proper wiring at electrical receptacles as well as to check the function of GFCI's.
An electrical receptacle which has been wired 'downstream' from a GFCI or AFCI will be protected by that device provided that the wiring has been connected properly.
We find often that these devices were not wired correctly. For example, reversing the "line" and "load" wiring when installing a GFCI will prevent it from functioning properly even though the installer may test it and think it's fine.
Testing GFCIs on Un-Grounded Knob and Tube Electrical Circuits
A ground fault circuit interrupter can provide shock protection for an electrical circuit that has no ground present, such as a knob and tube electrical circuit.
The GFCI device will still work if it detects a current leak to ground - say if an occupant drops their hair dryer into the sink (which is full of water grounded via the building plumbing system).
But can you test the GFCI protection feature of a GFCI receptacle installed on a knob and tube circuit
There are two "answers":
No: the GFCI test device or internal GFCI test exercised by the test button depends on being able to produce a small internal current leak to ground. Since there is no electrical ground wire present, the test feature won't work.
Yes, sort-of: you could rig your own test of a GFCI device on a knob and tube or other un-grounded circuit by making a connection from the hot lead of the receptacle to a known ground such as a water pipe or radiator. We've demonstrated this procedure using a test instrument as well as a bare wire. DO NOT DO THIS unless you are specially trained and equipped to do so. It is dangerous for various reasons including the chance that you or a bystander will be killed by electric shock.
There have been some recalled GFCI devices that would not work reliably. If you had the bad luck to try your amateur test on one of these, the results could be a disaster. See SQUARE-D RECALLS.
AFCIs: The requirement to inspect and test AFCIs is already in some regulations for home inspectors. It seems likely that remaining home inspection associations and state or provincial inspection standards-writers will soon update their electrical inspection standards section to address the new requirement for AFCI's.
See AFCIs ARC FAULT CIRCUIT INTERRUPTERS for details of the electrical code changes regarding the requirement for arc fault interrupters in homes.
AFCIs can be properly tested only by using the test button on the device itself. External tool tests are incomplete and therefore unreliable.
There have been some recalled AFCI devices that might not work reliably. If you had the bad luck to try your amateur test on one of these, the results could be a disaster. See this Federal Pioneer AFCI recall issued by Schneider Electric.
General Electrical Safety Suggestions describes important basic safety procedures, clothing, and equipment for home inspectors and electrical inspectors.
Using a DMM or VOM to Check for Current
A simple volt ohm meter volt-ohmeter (VOM) such as the TriplettTM 310
or our little mini digital multimeter (DMM) shown at left can be used to test for unexpected and unsafe voltage at a component.
Set the VOM in the highest AC-voltage
range.
One probe is used to contact the surface of the electric panel (or any component to be examined)
The other probe is touched to a
reliable ground source, or in the example shown, to the neutral side of the circuit.
NOTE: Once having tested at the highest voltage range, greater accuracy may be obtained by choosing more sensitive
ranges which permit readings to be taken in the upper portion of the scale. Disconnect the test probes (or shut off the voltage source)
before changing the voltage range setting on the VOM.
For example, if the meter indicates more than 1or 2 volts between a service panel cover and ground, there's a safety problem. Most low-cost
analog-type meters such as the one described provide additional ranges
used to read lower voltages with more sensitivity.
Some VOM models provide alligator clips for the ends of the test probes. These clips permit measuring high voltage without handling
the probes. Always shut off the power before connecting the alligator
clips.
Safe Use of Electrical Test Equipment: DMMs & VOMs
8.3 During an electrical system inspection the inspector is NOT required to
8.3.A. insert any tool, probe, or testing device inside the panels
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A simple volt ohm meter volt-ohmeter (VOM) such as the TriplettTM 310
or our little mini digital multimeter (DMM) shown at left can be used to test for unexpected and unsafe voltage at a component.
Set the VOM in the highest AC-voltage
range.
One probe is used to contact the surface of the electric panel (or any component to be examined)
The other probe is touched to a
reliable ground source, or in the example shown, to the neutral side of the circuit.
NOTE: Once having tested at the highest voltage range, greater accuracy may be obtained by choosing more sensitive
ranges which permit readings to be taken in the upper portion of the scale. Disconnect the test probes (or shut off the voltage source)
before changing the voltage range setting on the VOM.
For example, if the meter indicates more than 1or 2 volts between a service panel cover and ground, there's a safety problem. Most low-cost
analog-type meters such as the one described provide additional ranges
used to read lower voltages with more sensitivity.
Some VOM models provide alligator clips for the ends of the test probes. These clips permit measuring high voltage without handling
the probes. Always shut off the power before connecting the alligator
clips.
Safe Use of Electrical Test Equipment: DMMs & VOMs
8.3 During an electrical system inspection the inspector is NOT required to
8.3.A. insert any tool, probe, or testing device inside the panels
How to Test digital volt meter DMM or Volt Ohm Meter VOM meter condition
In some circumstances ASHI inspectors may elect to make
current and voltage measurements. For inspectors who elect to use
these tools, make sure that the tools themselves do not become a source
of damage, or injury.
Use only DMM's (digital multi meters) or VOMs (volt-ohm
meters, the analog predecessors to DMMs) designed for high energy
measurements.
These electrical inspection suggestions are not a complete inventory of all electrical components that should be inspected; these notes focus on identification of conditions that may present special electrical hazards for the electrical inspector. Contact Us by email to suggest changes, corrections, and additions to this material.
General Safety Suggestions for Electrical Inspectors
Pay attention, look carefully, move slowly before opening or exploring electrical equipment. Learn to recognize indications of a problem, such as but not limited to the examples in this article.
Do not assume anything when performing dangerous tasks such as inspecting electrical equipment.
Do not assume that electrical power is "off" without confirming that using proper test equipment and methods
Do not assume that system grounding is complete and correct
Do not assume that all circuit breakers and GFCI's and AFCI's will work
Do not assume that bystanders or clients won't move suddenly into the path of danger, or push you into it.
Do not touch live wires or connections. Watch your hands and other body parts. Handling live electrical wires without special training and equipment
is highly questionable and often fatal.
December 12, 1988 - Madison, WI - Michael E. Hammes, 26, died in an
apparent electrocution while working in Madison. Hammes had been hired
by CUNA Mutual Insurance Society to change ballasts on fluorescent
lights. Authorities said he was replacing a fixture in a fourth floor
bathroom while standing on a stepladder when he slumped to the floor.
Hammes apparently was electrocuted when he touched live wire with
one hand and a metal partition with his body or other hand, according
to Dana County Coroner Ray Wosepka.
Hammes was a first-year electronics
student. Wosepka said his investigation showed the light fixture had
been properly wired. Hammes apparently replaced a ballast, a [transformer]
that controls the electrical flow to the light bulbs, and was attaching
the live wire when it electrocuted him, Wosepka said. -- Ibid.
If in your opinion unsafe conditions exist at a property you are inspecting
you should notify all parties concerned, including building occupants/management/owners,
realtors involved, and other appropriate authorities.
December 18, 1988 - Smyrna, GA - A Smyrna family's troubles with a
faulty circuit breaker in their mobile home ended in tragedy when
a fire broke out and killed 18-year-old Jeffrey Scott Auton. Auton's
family, experiencing problems with the main circuit breaker, went
to a home products store to buy a new one for their trailer, said
Fire Investigator David Herndon.
The store did not have a circuit
breaker to fit the family's needs and a new one had to be ordered.
.... Herndon said the fire was started when the circuit breaker shut
down completely as three space heaters were running. The family had
a history of problems with the breaker, particularly from a load put
on it by a large heating unit. Herndon stated that after the fire
there was not a trace left of the circuit breaker; it was completely
gone from
the panel. -- Ibid.
For example, what if the case above had happened the day after the
property described had been examined by an ASHI inspector? Were there
perhaps clues which telegraph a developing problem? What about anecdotal
reports from the occupants of recurrent breaker tripping, visible
signs of overheating in the panel, widespread and unusual use of electric
heaters, or evidence of work in the panel by untrained people? These
risks to occupants are also a hazard to the inspector on several
bases.
Protect yourself and your client from injury using but not limited to the suggestions we provide here and just below.
Electrical Inspection Safety Suggestions from Rex Cauldwell, a Master Electrician
OPINION-RC: "As a master electrician, here is how I teach opening a service panel in my seminars: "The lucky 7""
Eye protection: Wear safety glasses--electrical panels have been know to explode upon opening.
Insulating gloves: Wear rubber dishwashing gloves--panels have been known to become electrically hot as a screw falls when cover is removed.
Look before touching: Don't approach the panel until you give an overall look of the surrounding area to see if
anything looks wrong--such as water on the floor under the panel.
Avoid Shock Pathways: Don't have any part of your body touching items adjacent to the panel.
Insulating floor pad: On a concrete or dirt floor, lay down a thick rubber Welcome mat and stand on it as you
open the panel (wear rubber-soled shoes).
Insulating tools: Use insulated handle tools--I use a Milwaukee electric screwdriver.
Panel Door & Screws: Once door is open (in a Federal Pacific panel (and some other models) beware of falling trim and breakers that pop out),
set door aside and don't lose the screws
Further Safety Warning--DF: these are helpful electrical safety suggestions from an experienced electrician.
No list of suggestions is incomplete and these presume that they are being
followed by an experienced, licensed electrician.
For example, there are almost certainly
gloves and/or boots specifically recommended for this application; there are specific safety details
to look at and for before touching an electrical panel, and procedures for using electrical test
equipment to test or examine a suspect electrical panel.
A home inspector or electrical inspector who has reported a very
unsafe condition, recommended immediate action, and
yet may later learn that occupants of the building were nearly killed by
work by an incompetent repairman. [NOTE: Port Jervis, NY, AHS Ctl#4658911,
7/10/90.] What can be done to reduce the chance of this terrible consequence?
Recommending action on an unsafe condition can convert a pre-existing
problem into an immediate catastrophe if the client or owner calls
an untrained person to the property or if he attempts a do-it-yourself repair.
Often a referral to local fire
inspector, electrical inspector, or utility company can help assure
that repairs are prompt, proper, and safe. If you recommend immediate
action for an unsafe condition, where possible you should provide
some means for the client or building owner to assure that the action
which is taken is proper and safe.
Inspectors are properly nervous and reluctant to prescribe the actual repair that is needed at a property - they may not know the detailed repair procedure, or there may be alternative repairs, or their description may prompt an un-trained person to try to do the work.
The Building Owner or Building Manager Needs to Know About Unsafe Conditions that Need Immediate Action
What kind of trades person, utility worker, or other technician is proper to perform the necessary repair?
What steps should be taken by the building owner or manager to assure that the repair is proper and safe?
Is there an independent follow-up authority such as a fire inspector, utility company representative, or building code compliance inspector who should examine the repair?
Are there well-known and common foul-ups in repair, or local inept repair companies against whom the owner should be warned?
The inspector should inform the appropriate parties both orally and in writing any suspected unsafe conditions.
If an area or component could not be fully inspected, the inspector should explain in writing why she or he
did not enter or examine an area or component, and what additional inspections or steps should be taken, as well as the general risks that may be present.
Handling Immediate Threats to Life and Safety at a Building Inspection
If in the inspector's judgment equipment is an immediate threat to life and property, such as a boiler whose flue connection has fallen off, we recommend that dangerous equipment be shut down and the appropriate people notified. See Shutting Down Unsafe Equipment. In some cases "appropriate people" includes not only the client and building owner, but also building occupants.
In some instances such as sparking electrical panels, gas leaks, or evidence of a fire, the inspector and everyone else should leave the building immediately and from outside, call the fire department and as appropriate, the gas company, police, or rescue personnel.
Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
Additional technical contributors & reference sources for this article are listed below.
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
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
"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 mrelectricwa@gmail.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 protune@aol.com
Rex Cauldwell, master electrician and contributor to the Journal of Light Construction on 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
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
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)
Aluminum Wiring Information Website Aluminum Electrical Wiring Hazards and Repairs: in-depth authoritative info, photos, documents including selection of proper vs. ineffective repair methods. E.g.: Ideal 65 "Twister" purple connector fails in field and lab testing with aluminum wire.
Circuit Breaker, a bad one fails to trip failure at aluminum bus-to-circuit breaker connection - field report and photographs
Electrical Panels, How to Inspect in buildings, safety for electrical inspectors, electrical panel, fusing, wiring defects, defective products. Inspection Class Presentation
Federal Pacific Electric (FPE) Stab-Lok Circuit Breaker Panel Hazards Website - Latent fire hazards, in-depth authoritative research, documents, advice on Stab-Lok electric panel and circuit breaker failures and what to do when this equipment is found in buildings.
"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.
"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.
"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.
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