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Guide to electrical test tools for electricians, service technicians, building inspectors: this article discusses several inexpensive and useful test tools for the electrical inspector, home inspector, or other professionals who examine residential electrical systems.
Guide to Using Electrical System Test Equipment to Check Electrical Equipment, Components or Electrical System Safety
Fatal Shock Hazard Warning: Inspecting electrical components and systems risks death by electrocution as well as serious burns or other injuries to the inspector or to others. Do not attempt these tasks unless you are properly trained and equipped.
Proceedings of the ASHI Home Inspector Educational Seminar: ASHI-NE Chapter Annual conference,
September 22-23, 2008, Randolph, MA. -- Daniel Friedman.
Original text - Daniel Friedman, as ASHI Technical Journal Staff, January 1992,updates February 2006, September 2008.
This is the full text version. A powerpoint presentation version of this class is also available.
These electrical inspection suggestions are not a complete inventory of all electrical components that should be inspected; nor have we described all of the electrical test tools popular among home inspectors and electrical inspectors.
For example the SureTest® Circuit Analyzer model 61-164 and 61-165 made by the Ideal Corporation is quite popular among many home inspectors. (We'd welcome a contribution on the proper use of this tool.) Sometimes circuit analyzers are misused in testing aluminum wiring, FPE Stab-Lok equipment and AFCIs. Contact Us by email to suggest changes, corrections, and additions to this material.
First use your head: stop, look listen, before touching anything, use safety equipment
Stop, look, listen before touching. More on "just looking" is provided when we discuss opening the electrical panel. Do not rely on touch to determine if electrical equipment is safe.
Details about the hazards of touching electrical equipment and alternative advice for determining whether or not equipment is safe to inspect are provided at Touching Electrical Equipment.
Guide to Using a Tic Tracer™ to Test for Presence of Electrical Voltage
This is a superb safety tool for testing for the presence of live 120VAC or 240VAC because you do not actually need to touch the tool to anything - just hold the tool near a source of electrical power and the electrical field produced will cause the tool to generate its tone. Faster "ticking" indicates higher voltage; slow ticking can indicate a wire connected to a live circuit even if the wire is not presently conducting current.
With practice the inspector can guess the voltage level from the tone quality.
We use this tool to check light sockets for power when there is no bulb or the bulb is dark. We also use this tool to look for lost or hidden wiring in walls and ceilings.
Its sensitivity falls off with the square of the distance from the source of electrical power.
Weird and interesting behavior of the TIF Tic Tracer: Some ASHI NE chapter inspectors pointed out that this device can be "fooled" into thinking that a wire scrap is "live" or that even a pipe is electrically "live" when it is not.
If a live electrical wire passes close enough to another metal device such as a pipe, electrical conduit, or armored cable, the metal device, conduit, or cable may pick up the electrical field generated by the "live wire" and appear "live" itself when it is not. (This is a "safe" error in that it errs in the direction of warning that something is live when it is not.)
This tool will also respond to momentary static electricity. In winter, simply rubbing its tip quickly across a wall can produce a momentary sound response. (Which can be fun in certain circumstances.)
The Tic Tracer™ is discussed further along with examples of how this tool is used at TOUCHING EQUIPMENT. Inspectors who object to the "false positive" possibility make use of a light-pen or similar tool which performs similar functions with less sensitivity to false positives.
Guide to Using Non-Contact Voltage Sensing or Voltage Detection Tools
Alternative AC and DC non-contact voltage sensing tools including pen-sized current sensors and even the simple neon-tester, below are available to perform this function.
The Tif™ Tic Tracer™ and other inexpensive pen-type voltage sensors (GB® non-contact voltage sensor, Greenlee Voltage Detector, Sperry® non-contact voltage sensor, Global Cache™, PasPort® and FCB Voltage Pen (Photo at left)), offer the advantage that it is not necessary to actually touch equipment, a surface, or a wire, to sense the presence of live voltage. Some voltage sensing models incude an adjustment to the sensitivity of the device.
SAFETY TIP: Greenlee and other manufacturers recommend that you test the operation of the voltage detector on a known live circuit both before and after using it to test for the presence of electrical voltage at a wire or device.
Guide to Using a Neon Tester to Test for Live Voltage or for Ground Paths
A simple neon tester is perhaps a simple, versatile tool for checking for the presence or absence of voltage. It requires touching electrical contacts or grounded surfaces to function.
Just touch one leg of the tester to the surface to be checked (a wire terminal or an electrical panel enclosure). Touch the second leg of the neon tester to a sure-ground such as a water pipe that you see continues into soil. If voltage is present within the range of sensitivity of the neon tester's bulb, the bulb will light.
Neither of these neat little electrical test tools can be relied on to report low levels of current leakage.
At an investigation of a garage roof that shocked a crew of builders during reconstruction after a lightning strike, we measured voltage varying between about 38 volts AC and 68 volts AC between some framing components and the earth. We could not detect these conditions with a neon tester. A VOM or DMM was needed.
Introduction to 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
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
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
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
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Questions & answers or comments about using multimeters, digital multimeters, and volt-ohm meterrs safely during building electrical systems inspection, testing, diagnosis, or repair.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Simpson 260® Series 6XLM
Volt-Ohm-Milliammeter Instruction Manual, retrieved 9/5/2012, original source: http://www.simpsonelectric.com/uploads/File/datasheets/260-6xlm.pdf, [copy on file as Simpson_260-6xlm.pdf]
 Roger Hankey is principal of Hankey and Brown home inspectors, Eden Prairie, MN. Mr. Hankey is a past chairman of the ASHI Standards Committee. Mr. Hankey has served in other ASHI professional and leadership roles. Contact Roger Hankey at: 952 829-0044 - firstname.lastname@example.org. Mr. Hankey is a frequent contributor to InspectAPedia.com.
 Arlene Puentes, an ASHI member and a licensed home inspector in Kingston, NY, and has served on ASHI national committees as well as HVASHI Chapter President. Ms. Puentes can be contacted at email@example.com
 ASHI Technical Journal, Vol. 2. No. 1, January 1992, "Determining Service Ampacity," Dan Friedman and Alan Carson,
 ASHI Technical Journal, Vol. 3. No. 1, Spring, 1993, "Determining Service Ampacity - Another Consideration," Robert L. Klewitz, P.E.,
with subsequent updates and additions to the original text ongoing to 2/19/2006. Reprints of the originals and reprints of the Journal are available from ASHI, the American Society of Home Inspectors www.ashi.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.
 "Electrical System Inspection Basics," Richard C. Wolcott, ASHI 8th Annual Education Conference, Boston 1985.
 "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.
 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 firstname.lastname@example.org
 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.
"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.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Electrical Books section of the InspectAPedia Bookstore. (courtesy of Amazon.com)
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.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
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.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
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