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Touching Electrical Equipment - Safety Hazards and Electrical Inspection Procedures
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• Safety advice on touching electrical components

This article reviews safe and unsafe methods for touching or not-touching electrical equipment during its inspection. This is a sub-chapter of our article on electrical safety procedures which discusses safety hazards at residential electrical panels and suggests safety procedures for the electrical inspector, home inspector, or other professionals who examine residential electrical systems.

The gruesome death by electrocution shown in the photograph occurred when the man shown tried to steal electrical power from a high voltage cable. - Jim Simmons

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. Original text: DF, as ASHI Technical Journal Staff, January 1992, with updates February 2006. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links 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.

Touching electrical equipment during an inspection

Never touch metal plumbing or gas system pipes while you're working around electricity. Never touch electrical equipment while standing on a damp or wet surface.

During an inspection an ASHI inspector warned the home owner that there was a short in a florescent ceiling light fixture. The owner, a contractor who had done his own electrical work, irritated and incredulous at this supposed defect, licked his knuckles and bridged a small space between the light body and a nearby gas pipe. He's now a believer. [NOTE: DJF home inspection, Beacon, NY 1990]

A very questionable procedure is suggested in The ASHI Training Manual [NOTE: "Electrical Systems," ASHI Training Manual, chapter by Alfred L. Alk, p. 18. ASHI 1987] indicating that the inspector can "test" to see if a panel is dangerously "live" (has an internal short) by tapping the box with the knuckles of his/her right hand to check for current, then laying the right palm on the box to feel for heat before beginning to remove the cover. Don't do this!

From a safety view, this is a bad idea. Never rely on physical touch to judge electrical safety of a component. Use instruments. Test instruments such as the VOM described above, and the TIF^TM Tic Tracer shown at left are inexpensive, effective, safer when used properly. [NOTE: Alexandra Radkewycz, a Canadian researcher, reports severely shocking experiences from failure to make proper use of instruments. [Private communication to author, 12/91.]

Touching Electrical Equipment During an Inspection?

• Never touch metal plumbing or gas system pipes while you're working around electricity.
• Never touch electrical equipment while standing on a damp or wet surface. [Unless you are trained and are wearing appropriate protective gear.]

Shocked homeowner: During an inspection an ASHI inspector warned the home owner that there was a short in a florescent ceiling light fixture. The owner, a contractor who had done his own electrical work, irritated and incredulous at this supposed defect, licked his knuckles and bridged a small space between the light body and a nearby gas pipe. He's now a believer. [NOTE: DJF home inspection, Beacon, NY 1990]

Amazing Alk: A very questionable procedure is suggested in The ASHI Training Manual [ "Electrical Systems," ASHI Training Manual, chapter by Alfred L. Alk, p. 18. ASHI 1987] indicating that the inspector can "test" to see if a panel is dangerously "live" (has an internal short) by tapping the box with the knuckles of his/her right hand to check for current, then laying the right palm on the box to feel for heat before beginning to remove the cover. DO NOT RELY ON THESE UNSAFE METHODS.

From a safety view, this is a bad idea. Never rely on physical touch to judge electrical safety of a component.

In the same ASHI Training Manual chapter the author, Al Alk, offers another more accepted suggestion: "Inspectors should practice working around open enclosures with the left hand behind the back. If the right hand receives a shock the current will more likely pass down the right half of the body: the heart is on the left side. Inspectors who wear rings must be especially wary when working near an open box." [NOTE: ASHI Training Manual, Op. Cit.- Obsolete]

Grounding: A basic rule for working around electrical equipment: if you are yourself not grounded, and if you only touch one single component at a time, risks are reduced. Never ground yourself through your feet. Don't stand on a wet floor. If it's necessary to touch electrical components in such a location, a trained electrical worker uses a dry ungrounded platform such as boards or a wooden ladder.

Rings and watches: When working around electrical equipment, first remove rings and watches to reduce the risk of electric shock. At an IBM test site in Poughkeepsie, NY in the 1980's a test technician was killed while working on a computer. His metal watch band contacted a live component while other body parts were touching a grounded component, possibly the steel frame of the assembly. Similar accidents around electric panels are a real risk for home inspectors.

Electric Panel cover screws: if you find that a sharp-tipped sheet metal screw has been used (usually to replace a lost original fastener) you should be alert for pierced, damaged, short-circuited wires in the panel - both during removal and during panel cover replacement. We will not reinstall a sharp-pointed screw in a panel cover if wires are crowded close to the screw opening. Having seen more than one shorted and burned panel from precisely this cause, we warn clients about this unsafe detail. It is trivial to correct.

Never Assume You've Turned Power Off - Use a Neon Tester, Voltage Detector, or Multimeter

The most basic electrical safety procedure I can think of when working on electrical devices or electrical wiring involves knowing how to:

• turn off power to the device or circuit or system where you're planning to work
• make sure that power is really OFF there

I never touch something electrical that I've "turned off" without using at least a neon tester to or a voltage detection pen to see that electrical power is really off. In 1970 I turned off power to a junction box to fix a light - the light went out - so I figured that all electrical power to the junction box was really off. Then while wiggling wires in the junction box I got a huge spark and a little shock.

Some nitwit had run two different live circuits into the same junction box.

Now I'm more careful. I figure that if you don't electrocute yourself, the rest is easy - you can always run out of a burning building. Well really inspectors have more responsibility than that: in addition to not killing yourself, you must protect the safety of your clients and of the occupants of buildings on which you've performed work.

VOLTAGE by EQUIPMENT describes voltage sensors, DMMs, VOMs, and other choices of equipment we use for testing electrical circuits and for performing basic electrical or appliance wiring repairs.

General Electrical Safety Suggestions describes important basic safety procedures, clothing, and equipment for home inspectors and electrical inspectors.

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SAFETY: ELECTRICAL INSPECTION SAFETY
  Shock Risk Statistics
  Outside Electrical Inspection
  Electric Meter & Service Entry
  Local Electrical Grounding
  Electrical Panel Interior Inspection
  Removing Electric Panel Covers
  Electrical Panel Cover Screws
  Electrical Panel Interior Hazards
  Testing Main Breakers or Fuses
  Inspect Breakers, Fuses, Circuits
  Testing Receptacles GFCIs AFCIs
  When to Shut Down Equipment
  Touching Electrical Equipment
  Guide to Electrical Test Equipment
  Using DMMs & VOMs Safely
  Voltage Measurement & Detection
  General Electrical Safety Suggestions
  Electrical Inspection Client Safety

• 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 (eg, 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

• Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
• "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 mrelectricoly@msn.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]
• Critique, contributions wanted: Contact Us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution.

More Information on Building Diagnostic Inspections and Repairs

• * Safety Hazards and Safe Inspection Procedures for Electrical and Home Inspectors at Residential Electric Panels
• 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.
• Ampacity of an Electrical Service: How to determine the electrical service size or ampacity entering a building
• 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.
• Lightning Strike Risk Assessment, Protection Systems & Services
• Multi-wire branch circuit inspection and defects
• Rust and Corrosion in Electrical Panels, A Study and Report on Frequency and Cause for Electrical and Home Inspectors at Residential Electric Panels
• "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.
• Electrical System & Wiring Hazard Inspection, Detection, Cause, Remedy, Prevention - Main Electrical Page

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