Electrical Engineering

Introduction

Forensic electrical engineering is the practicalapplication of electrical engineering knowledge tolegal questions about electrical phenomena. Practicalelectrical engineering knowledge is obtained fromexperience in designing, installing, maintainingand repairing electrical devices, appliances, andequipment. Reports, demonstrations, depositions,and court testimony are used to explain electricalphenomena to insurers, attorneys, arbitrators, judges,and juries. The area of practice extends from softwarefor computers to the generation and distributionof electrical power, which might be controlled bysoftware, and to consumer products.

The electrical engineer explains how the electricalsoftware, equipment, or device functions normallyand why it malfunctioned, violated a copyright, orfailed in this instance causing damage, financial loss,injury, or death. In some instances, the electricalengineer might be retained by a client to verify thatelectricity was not involved with the cause of afire, damage, or injury. Quite frequently, electricalengineers must use mechanical, thermodynamic, andoptical knowledge to answer questions since thegeneration, distribution, and utilization of electricalpower involves mechanical components, which canproduce heat and light.

History

The investigation of electrical phenomena began inEurope in the seventeenth century [1]. The first elec-trical investigators were called electricians. At thetime electricity was believed to be fire, “fulmen ful-minis” or fire of fire and lightning was fire fromthe sky, the wrath of God].a St Paul was struckby lightning in 33 AD while traveling to Damascusto suppress Christianity. On regaining his sight, StPaul was baptized and immediately began preach-ing Christian theology.b On July 2, 1505, lightningstruck near a happy-go-lucky law student, MartinLuther. Fifteen days later, Martin Luther entered theBlack Monastery in Erfurt, Germany [2]. Churchbells often were inscribed with a Latin phrase, Ful-gura frango, which when translated means, “I break

up the lightning”. A treatise on the subject by amedieval scholar titled “Proof that the ringing ofbells during thunderstorms may be more dangerousthan useful”, found that over a 33-year period inGermany, a total of 386 lightning strikes on churchtowers killed 103 bell ringers [3, 4]. In 1767, a churchin Venice storing 100 t of gunpowder was struckby lightning, 3000 people were killed and a largesection of the city destroyed [5]. Benjamin Franklinperceived and proved that lightning is an electri-cal phenomenon. He devised the famous sentry boxexperiment in 1749, which clearly displayed the elec-trical nature of lightning [6]. When he reported hisfindings, the King of France, Louis XV, who was anelectrical fanatic, had a sentry box built in 1752, andsubsequently Franklin’s experimental findings wereverified in Europe [7, 8]. Benjamin Franklin madeon-site inspections of churches, which were struckby lightning, [9] wrote newspaper articles request-ing information about lightning damage.c and readarticles about lightning damage to churches to deter-mine the effectiveness of bell ringing [10].d Franklinfound that bell ringing during a thunderstorm is avery dangerous occupation. If metal wire was usedto ring the bells, the lightning would vaporize it butnot damage anything along its path but killed the bellringer. However, if rope was used to ring the bells, thelightning would cause severe damage to the steeplebut probably not kill the bell ringer. This is whereFranklin got the idea to attach metal wire to his rod.Franklin rods were opposed by church clergy on theirstructures because it seemed a sacrilegious act and anexpression of no confidence in the mercy of God instriking a sacred structure. However, a Franklin rodwas installed on a building in Venice (Campanile ofSan Marco) that had been struck and severely dam-aged by lightning nine times from 1388 to 1762.Since the installation of a Franklin rod in 1766, ithas not been damaged by lightning [3, 4]. Franklininspected buildings protected with a Franklin rod,which resulted in Franklin writing the first specifi-cations or standards improving lightning rods [11].

Electrical engineering emerged as a discipline in1864 when the Scottish physicist and mathematicianJames Clerk Maxwell summarized the basic laws ofelectricity in mathematical form and predicted thatradiation of electromagnetic energy would occur in aform that later became known as radio waves.

The first practical application of electricity was thetelegraph, invented by Samuel B. F. Morse in 1837.

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However, there was not a great need for electricalengineers until the inventions of Alexander GrahamBell and Thomas A. Edison approximately 40 yearslater; Bell’s telephone in 1876 and Edison’s incan-descent lamp in 1878 and the first central electricgenerating plant in New York in 1882. Overnighta large demand was created for men educated andtrained to work with electricity [1]. During the 1890s,engineering schools all over the world added studiesin electrical engineering, often as optional courseswithin the mechanical engineering field. Previously,the study of electricity was considered to be a sub-field of physics. Academic departments of electricalengineering emerged around the turn of the cen-tury [12]. In 1883, Cornell University introduced theworld’s first course of study in electrical engineer-ing and, in 1885, the University College, London,founded the first chair of electrical engineering inthe United Kingdom [13]. The sudden explosion ofthe electrical industry generated a need for electri-cal experts to answer legal questions about electricaldesigns, patents, contracts, personal injury, and dam-age. The adversarial legal system permitted eachparty involved in litigation to retain their own elec-trical expert as opposed to other legal systems wherethe judge appoints the expert to assist with techni-cal questions. In addition, the ability of attorneys inthe United States to pursue litigation on a contin-gency basis and the subrogation laws of the UnitedStates increased the demand for forensic electricalengineers.

Electrical litigation started with patent disputesand Lewis Howard Latimer was probably the firstelectrical engineer to testify in a patent dispute [14].It is possible that there were earlier trials wheresomeone was qualified in electrical engineering, butwithout an appeal that there is no documentation.

Education, Training, and Certification

There is presently no formal program for a Bachelorof Science degree in forensic electrical engineering.In the United States, the basic educational require-ment for a forensic electrical engineer is normallya Bachelor of Science degree in electrical engineer-ing from an accredited university. A few universi-ties in the United States offer graduate courses inforensic engineering. The University of Iowa has aBiomedical Engineering Program. The University of

Texas at Tyler has “Advanced Topics in Engineering(introduction to forensic engineering)”. The Univer-sity of Colorado at Denver offers “Failure Analysisand Condition Assessment in Civil and Mechani-cal Engineering”. Purdue University’s Weldon Schooloffers a course to seniors and graduate students titled“Medical Device Accidents and their EngineeringAnalysis”.

In addition, the individual should be a licensedprofessional engineer since state laws in the UnitedStates require engineers who work independently tobe licensed. The requirements for licensing differamong the states.

In Canada, the engineering students normally taketheir professional engineering test in the senior yearof their educational program.

Typically, engineers get involved with forensicwork by joining a consulting firm, which specializesin forensic engineering, or associating with practic-ing forensic engineers. The senior members of theconsulting firm or practitioners provide the trainingneeded by the degreed and experienced engineer inthe aspects of forensic engineering.

In 1997, the National Academy of Forensic Engi-neers (NAFE) appointed a committee, the ForensicEngineering Curriculum (FEC) Committee, and sup-plied funding to develop guidelines for universitycourses in forensic engineering. The FEC Committeedetermined that any forensic engineering degree pro-gram should begin at the masters degree level becauseof the specialized nature of forensic engineering.

Education and training for forensic electrical engi-neers is also available through various technical,legal, and forensic societies. The Institute of Electri-cal and Electronic Engineers (IEEE), conducts sem-inars and lectures on electrical equipment and theproblems associated with the equipment. NAFE hasseminars twice a year where technical papers arepresented about forensic engineering investigations.The academy also publishes a journal of the papersthat were presented at the seminars. Many of thepresentations and published papers involve electri-cal engineering. The American Academy of ForensicSciences (AAFS) has an engineering section. Theengineering section of AAFS presents papers aboutforensic engineering investigations at their annualmeeting each February. The AAFS has workshops attheir annual meeting and sometimes the workshopsinvolve some aspects of electrical engineering.

Electrical Engineering 3

Certification in forensic electrical engineering inthe United States is provided by NAFE throughthe Council of Engineering and Scientific SpecialtyBoards. Subsequently, members of NAFE can refer tothemselves as a Board Certified Diplomate in forensicengineering by NAFE, program accredited by Coun-cil of Engineering and Scientific Specialty Boards(CESB). Another certification program is throughthe International Institute of Forensic EngineeringSciences, Inc., (IIFES). The IIFES maintains itscertification program through the Forensic SpecialtiesAccreditation Board. Forensic engineers who meetthe requirements of IIFES are awarded a Certificateof Qualification as a Diplomate, IIFES. They are thenentitled to represent themselves as being board certi-fied by the IIFES.

Societies, CPD’s and Sections

The largest forensic engineering society is NAFE.NAFE has approximately 400 members and 52 aredegreed electrical engineers. NAFE is a charteredaffinity group of the National Society of ProfessionalEngineers of the United States and all membersare licensed/registered professional engineers. Allmembers of NAFE must provide forms each yearreflecting that they have accumulated 100 continuingprofessional development (CPD) credits during thepast 5 years.

The AAFS established an engineering sciencessection in 1981. The AAFS engineering sciencessection has approximately 170 members and 20members are electrical engineers.

Casework

Electrical engineers are asked to answer legal ques-tions about electrical phenomena from charged parti-cles to the appliances in our homes and the electricalsystem that supplies them with power. The questionsmight be asked verbally or in written statements bya client to determine if further investigation or lit-igation should be pursued. Most of the caseworkinvolves civil litigation and the majority of the clientsare insurance companies and their attorneys. Theengineer is contacted by telephone, email, and faxmachine by claim/loss adjusters, attorneys, publicdefenders, manufacturers, private investigators, mil-itary investigators, law enforcement, and individuals

who are handling a matter involving financial loss,violations of law, or personal injury/death. The matteris discussed with the potential client and the engi-neer informs them if they can provide any assistancein the matter. The client usually requires a curricu-lum vita (CV) (resume) to check if the engineeringeducation, training, and work experience would qual-ify them to be declared an expert witness in a courtof law involving the matter. Rate sheets (charges forservices) are almost always requested. If the clientdecides to retain the engineer, a contract should besigned between them, which details what service theengineer will provide to the client: inspection, inves-tigation, testing, analysis, reports, and/or testimony.

The subrogation laws in the United States permitinsurance companies to recoup the money they paidfor fire damage from individuals, companies, or man-ufacturers for improper/defective installation, use, ormanufacture of a product. Subsequently, most of theforensic electrical engineer’s casework involves fireinvestigation. Electrical engineers who investigate thecause of fires must also have training in fire investiga-tion. Fire investigation training is necessary becauseto determine the cause of a fire, the individual must beable to locate the origin of the fire (where it started).Examination of the electrical components, if any, atthe point of fire origin will usually reveal if elec-tricity was involved with the fire’s cause. Training infire investigation can be obtained through the Interna-tional Association of Arson Investigators (IAAI). TheIAAI holds annual fire investigation training semi-nars. It has state chapters throughout the United Statesand in other countries, which conduct fire investiga-tion training seminars.

Electrical injury and electrocution cases are nor-mally large loss matters exceeding several milliondollars but there are very few of them compared tothe number of fires.

Engineers evaluate electrical damage to determineif it is covered by an insurance policy or which pol-icy (fire insurance, boilermaker, or umbrella). If theverbal statement of the engineer is not sufficient toanswer the legal technical questions, then a writtenreport might be requested from the engineer to pur-sue the matter further. Normally, the report wouldinclude the scope of work to be performed, details ofthe investigation, any testing, research, analysis, andconclusions. The analysis might include an evalua-tion of different versions of events in the matter andtheir affect on the cause of the damage or injury. The

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majority of the cases settle after a report is submitted.However, a few go on to depositions where the engi-neer is asked questions under oath by the attorneysinvolved in litigating the case. Before the deposition,the engineer must educate his client attorney aboutelectricity and/or fire investigation. The client shouldunderstand how electricity caused the injury, damage,or fire and what laws, codes, or standards apply to thecase and if any were violated by any parties involved.At the deposition, the engineer is asked for their CVby the deposing attorney and they are questionedunder oath about the CV to evaluate their qualifi-cations to testify about the matter at hand. They areasked details about their case file, investigation, test-ing, and analysis. Hypothetical questions are askedto evaluate potentially different conclusions. Some-times, an estimate of the percentage of reliability ofthe conclusions is asked of the engineer.

Very few cases go to trial because of the cost ofpresenting a case in court. Some cases go to trialbecause the various parties have experts with drasti-cally different opinions, personal grievances, or askthe court to determine how the case should be set-tled. Before trial, the engineer might be asked tosubmit a list of casework, authored articles, depo-sitions, and trial testimony. At trial, the engineeris asked about their education, training, and profes-sional work experience by attorneys and sometimesjudges to determine if they are qualified to giveexpert witness testimony at the trial and on whatareas/subjects they can testify about. The judge deter-mines if the engineer qualifies as an expert witness.If qualified, the engineer answers technical questionsposed by his client attorney, opposing attorneys, andrarely the judge and jury to aid the jury and court intheir deliberations. During questioning by his client,the engineer must educate the judge and jury aboutelectricity, fire investigation, computer software, orwhatever is the subject of the litigation. The normaloperation of the electrical device should be explainedand also how it malfunctioned in this instance causingthe financial loss, injury, or death. Next, the engineeris questioned by the opposing attorneys who attemptto find errors in the expert’s testimony.

An example electrical injury case involved theloss of arms and a liability of $10–15 million. Anelectrical engineer was contacted by an independentadjuster retained by a supermarket company to assisthim or her with investigating the cause of the injury.Normally, property owners in the United States are

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Figure 1 Figure showing the front doors on the high-volt-age disconnect switch. Arrow 1 indicates the missing coverover the observation window of the switch. Arrow 2indicates a lock with a key broken off in it, which is shownin more detail in Figure 2. Arrow 3 indicates holes in thefuse compartment door, which is shown in more detail inFigure 3

liable for electrical damage or injury on their propertyand the injury occurred on supermarket property. Agroup of children had been playing behind a closedsupermarket where a 13 kV switch was located neara loading dock (Figure 1). The engineer was askedto determine why the injury occurred; if the electri-cal equipment was properly installed, maintained, ormanufactured and if not, what parties were at fault. Atthe injury location, the engineer saw that the switchdid not have a fence or additional enclosure around it,as required by electrical standards [15]. This indicatesthat the switch was improperly installed by the super-market’s contractors. The observation opening on thefront of the switch was missing a cover to keep waterout, arrow 1 in Figure 1. The switch operating handlewas in the closed position, arrow 1 in Figure 2. A keywas broken off in a lock that was mechanically linkedwith the position of the switch, arrow 2 in Figure 2.

Electrical Engineering 5

2

3

3

3

- 2658 D 2430

OPEN

TO REMOVE HANDLE

PULL AT HUB

CLOSED

1

NEWARK, NEW JERSEY,U.S.A.

LOAD INTERRUPTERSWITCH TYPE LI

- 600 A.- 13.8 K.V.- 40 KA- 60 HZ.- 14.5 K.V.- 95 K.V.- 600 A.

CAT.NO.CONT. RTG.NOM. VOLT.SHORT TIMEFREQUENCYMAX. DESIMP. WITH.INTERR. RTG.

Figure 2 Figure showing the operating handle of the switch. Arrow 1 indicates that the switch is in the closed position.Arrow 2 indicates the broken key in the lock. Arrow 3 indicates unsealed openings

Normally, the key can only be removed from the lockwhen the switch is in the open position. When theswitch is open, the key is removed from the lock andutilized to unlock another lock, which is securing thelower door of the switch where fuses are located.Additional unsealed openings were found around theswitch handle, arrow 3 in Figure 2. The switch’slower fuse compartment door had holes in it wherea lock that was controlled by the broken key shouldhave been located, arrow 3 in Figures 1 and 3. Thisindicates that the switch was not properly maintainedby the supermarket. Subsequently, the fuse compart-ment of the switch could be opened and entered whilethe switch was energized with 13 kV. Evidence ofburning, arcing, and melted metal was found at the

top of the left fuse holder in the fuse compartment(Figure 4). This is where the child’s right hand madecontact with 13 kV. Fingerprints in metal were foundon the left side of the fuse compartment opening(Figure 5). This is where the electrical current exitedthe boy’s left hand. The electrical current flowedfrom the top of the fuse holder through the boy’sarms to the side of the switch, which is grounded asrequired by electrical codes. This injury was causedby the improper design, installation, and maintenanceof the high-voltage disconnect switch, which violatedelectrical codes and standards. It was not designedfor outdoor use. The openings in its enclosure per-mitted water and debris to enter into the switch. Asingle-door design covering the fuse compartment

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Figure 3 Close-up figure showing the holes in the door of the fuse compartment and frame of the switch, as indicatedby the arrows in the Figure

Figure 4 Close-up figure showing the melted metal at the top of the fuse holder, as indicated by the arrows in the Figure

and switch operating handle would have eliminatedthe problem with the missing interlock lock on thefuse compartment door. The fuse compartment isrequired to be secured from entry when the switchis closed. The switch was designed for installation ina locked electrical room. However, it was incorrectlylisted in a utility company’s book of acceptableswitches for the location. A scheduled maintenanceprogram would have detected the switch’s deficien-cies and corrected them. This case settled out of courtwithout depositions or reports. The engineer edu-cated the supermarket attorneys verbally and with

printed documents about the improper installation,design, and maintenance of the switch and thecodes/standards that were violated. The education anddocuments enabled the supermarket attorneys to bringtheir contractors and the utility company to the bar-gaining table and share in the liability for the injury.

An example of a fire case involves a severe res-idential fire with a large property loss. A fire inves-tigator brought a box of items from the fire’s areaof origin to this engineer’s office. The fire investi-gator asked the engineer to inspect and photographthe items to determine if they were involved with the

Electrical Engineering 7

Figure 5 Figure showing fingerprints in metal, as indicated by the arrows in the Figure

Figure 6 Figure showing the bottom of the steam generating tank

cause of a fire. He also emailed photographs of thefire scene and his fire determination report to the engi-neer. Among the items was a severely heat-damagedsteam generating tank (Figure 6). The steam generat-ing tank was X-rayed (Figure 7). The X-ray showedthat the sheath (exterior enclosure) of the unit’s

heating element was open (arrow 1 in Figure 7) anda thermal over-temperature device had blown apart(arrow 2 in Figure 7). In addition, the nichrome wireinside the heating element was separated and disinte-grated in many locations (Figure 8). The nichromewire is the device that generates heat inside the

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Figure 7 Figure showing an X-ray of the steam generating tank. Arrow 1 indicates an opening in the sheath of the heatingelement. Arrow 2 indicates a thermal control device

Figure 8 Close-up figure showing the nichrome wire inside the heating element, as indicated by the arrows in the Figure

heating element when electric current passes throughit. Nichrome wire is a nickel-base alloy, containingchromium and iron. Nichrome wire has a meltingpoint of 1020–1452°C depending upon the chemicalcomposition of the alloy [16]. The fire temperatures ina residential building normally do not exceed 800°C.Subsequently, the disintegration of the nichrome wireinside the heating element indicates that the heat-ing element malfunctioned and caused the fire. The

engineer verbally reported his conclusions about theinspection and X-rays to the fire investigator and theinsurance company that retained him. An exemplarsteam generating tank by the same manufacturer waspurchased, inspected, and tested by the engineer. Theexemplar was found to be defective in design andmanufacture. An engineering report was requestedand submitted with photographs and X-rays. Thereport stated that the subject steam generating tank

Electrical Engineering 9

was defective in design, manufacture, and caused thefire. The manufacturer retained experts with differentopinions even after examining the evidence, X-rays,and exemplar. As a result, the engineer was deposedby the manufacturer’s attorneys and he educated themabout the appliance’s defects. The case settled afterthe deposition.

Another case involved a large residential buildingthat sustained fire damage while $500 000 worth ofrenovations was being performed. An electrical engi-neer was retained to investigate the origin and causeof a fire along with a fire investigator and mechanicalengineer for subrogation purposes. The building hadexperienced electrical problems and the fire was dis-covered just after the building’s new fireplace was litfor the first time. The fire originated within the wallsof the building where electrical wiring was located.The origin was in the concealed space above the newfireplace. Electrical wiring was located there to sup-ply electrical power to an outlet on the right sideof the fireplace. The wiring was solid copper andevidence of melting was found <2 cm apart on twowires (Figure 9). Melted copper between two elec-trical wires quite frequently indicates that the twowires short-circuited together. When copper wiringshort circuits, it generates temperatures exceeding1200°C with sufficient energy to ignite most com-mon combustibles. However, the evidence of meltingis normally at the same location along the length ofthe wire. Microscopic inspection of the melted areas

found that they were bite marks (Figures 10 and 11).Subsequently, an animal bit the wiring and producedthe short circuit, which ignited the building. The firewas the result of the renovation contractor leavingopenings to the interior of the walls unsecured duringconstruction after electrical power was supplied tothe building. The engineer determined the origin andcause of the fire and the party at fault, the renovationcontractor. However, no litigation followed becausethe building owner had signed a contract with therenovator that eliminated their liability for damagesthat occurred during the renovation.

Another example of an electrical injury caseinvolves an electrical explosion in an electrical distri-bution room that caused electrical injury and severeproperty damage (Figure 12). The engineer was askedby a law firm to inspect the scene of the explo-sion, evidence retained from the scene and researchdocuments to determine the cause of the explosionand the parties at fault for causing the personalinjuries of workers. The oil within a 5000-V oilcircuit breaker had exploded and ruptured its tank(Figure 13). The explosion occurred when the oilcircuit breaker was closed after maintenance was per-formed on it. The maintenance personnel were onlypermitted 30 min to work on the circuit breaker.Their maintenance consisted of draining the oil outof the bottom of circuit breaker and pumping newoil in. However, proper maintenance on this typeof oil circuit breaker requires a minimum of two

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Figure 9 Figure showing copper wires with melted areas. Arrow 1 indicates a melted area shown in more detail inFigure 10. Arrow 2 indicates a melted area shown in more detail in Figure 11

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1

Figure 10 Close-up figure showing the melted area indicated by arrow 1 in Figure 9

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Figure 11 Close-up figure showing the melted area indicated by arrow 2 in Figure 9

men working 4 h. The oil should have been putback into the tank from the top of the tank afterits interior was cleaned, inspected, and mechanicallytested. Furthermore, the electrical distribution roomshould have been cleared of personnel before thecircuit breaker was closed after maintenance. Con-sequentially, the property damage was caused by badmaintenance. The personnel injuries were the result ofnot following proper electrical protocol in closing theswitch after maintenance without clearing the area ofall unnecessary personnel. The engineer reported his

conclusions to his attorney client who did not requesta formal written report. Litigation against the main-tenance people was started and during the discoveryprocess the engineer was deposed by the mainte-nance attorneys. The engineer educated the main-tenance attorneys while testifying about their ownelectrical protocol, which required the injury area tobe cleared of all unnecessary personnel (the injuredworkers) before a high-voltage switch is closed aftermaintenance. After the deposition, the case settled outof court.

Electrical Engineering 11

Figure 12 Figure showing where an explosion occurred in an electrical room

Figure 13 Figure showing where the tank of the circuit breaker ruptured

The last example involves a severe fire in a com-mercial building with a large property loss. Thefire originated in an electrical distribution panel ina room of one of the commercial businesses inthe building. An electrical engineer was retainedby the insurance company who provided liability

coverage to the tenant of the commercial businesswhere the fire originated. The engineer was askedto determine the origin, cause, and parties at faultfor the fire damage. The owner of the building hadfiled a million-dollar complaint against the tenant.Most of the contents of the fire building had been

12 Electrical Engineering

removed prior to this engineer’s arrival at the firescene except for the main circuit breaker, which pro-tected the electrical conductors (wires) located withinmetal conduits (pipes) that feed electrical power todistribution panel previously located in the area ofthe fire’s origin. The burn pattern in the area of fire

origin indicated that the fire started in the ceilingarea above the distribution panel where a conduitcontaining the service conductors feeding the panelwas located. The service conductors were fused tothe bottom inside of the conduit that was in contactwith the structural wood components of the ceiling.

Figure 14 Figure showing the exterior of the circuit breaker

Figure 15 Figure showing the X-ray of the circuit breaker

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The conductors were separated from the conduit toperform tests on the circuit. The tests indicated thatthe conductors had short-circuited to the interior ofthe conduit all the way back to the main circuitbreaker. The main circuit breaker’s operating handlewas found in the closed position even though the con-ductors were not energized. Tests found no voltagepresent on the load terminals of the circuit breaker.Therefore, the local utility company was contactedto shut off power to the building so that the maincircuit breaker could be removed from the main pan-elboard for further testing. The main circuit breakerhad three phases and was rated at 200 A. No evi-dence of fire damage or overheating was found on

the exterior of the circuit breaker (Figure 14). Pre-liminary tests of the circuit breaker indicated thattwo of the phases (circuits) inside the circuit breakerwere open even when its operating handle was inthe closed position. The circuit breaker was X-rayed.The X-ray showed that internal components of twophases of the circuit breaker had separated and melted(Figure 15). The engineer reported the results of theinspection, testing and X-rays to the insurance com-pany adjuster. A report was requested with Figuresand X-rays. The manufacturer of the defective circuitbreaker was put on notice of the financial loss.Subsequently, the circuit breaker was disassembledwith representatives of its manufacturer present. The

Figure 16 Figure showing the interior of the circuit breaker after disassembly

Figure 17 Figure showing the internal components of an exemplar circuit breaker

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internal examination of the circuit breaker confirmedwhat the X-rays showed (Figure 16). An exemplarcircuit breaker was disassembled to compare internalcomponents. The components that melted and sepa-rated in the other circuit breaker were much lighterin color (Figure 17). The difference in color indicatesthat the separated components had overheated. Thecircuit breaker should have opened before its com-ponents melted and separated. A circuit breaker is “adevice designed to open and close a circuit by nonau-tomatic means and to open the circuit automaticallyon a predetermined overcurrent without damage toitself when properly applied within its rating”. Thecircuit breaker “is provided to open the circuit if thecurrent reaches a value that will cause an excessiveor dangerous temperature in conductors or conduc-tor insulation” [17]. The purpose of the main circuitbreaker is to open and disconnect electrical powerfrom an electrical distribution panel and the circuitfeeding it before the malfunction produces sufficientheat to ignite a fire in a building. Consequentially, thefire was caused by a defective main circuit breaker.The engineer answered the technical questions aboutthe origin, cause, and party at fault for the fire dam-age, the circuit breaker manufacturer. The case wassettled after disassembly of the circuit breaker withrepresentatives of the circuit breaker manufacturerpresent, engineers, and attorneys.

End Notes

a. Revelations 8: 3–5 and http://www.energycite.com/ben%20franklin.htm.b. Acts of the Apostles 8 : 1–3; 9 : 1–30; 22 : 3–21;26 : 9–23; Galatians 1 : 12–15.c. Franklin, B. Request for information on lightning,Pennsylvania Gazette, June 1753.d. Effect of lightning on Captain Waddel’s Compass,and on the Dutch Church in New York, from James

Bowdoin to Benjamin Franklin, Boston, 2 March1752.

References

[1] (1978). Encyclopedia Britannica, 15th Edition, Vol. 6,p. 536 ISBN: 0-85229-330-5.

[2] (2008). http://www.Luther.de/en/ and http://chi.goselcom.net.

[3] Matthews, J. (1998). Fear and lightning, Chain ReactionMagazine, 1, 22–23, http://chainreaction.asu.edu.

[4] Matthews, J. (2008). Fear of lightning grounded in myth,Arizona State University Research Magazine, http://researchmag.asu.edu/stories/lightning.html.

[5] Sechel, A.L. & Edwards, J. (2008). Franklin’s UnholyLightning Rod, http://evolvefish.com/freewrite/franklgt.htm.

[6] Golde, R.H. (1977). Lightning, Academic Press, Vol. 1.[7] Krider, E.P. & Franklin, B. (2005). in Search of a Better

World, P. Talbott, ed, Yale University Press, New Haven,Chapter 5.

[8] Cohen, I.B. (1990). Benjamin Franklin’s Science, Har-vard University Press, Cambridge, Chapter 6.

[9] Golde, R.H. (1977). Lightning, Academic Press, Vol. 1,pp. 170–172.

[10] Morse, R.A. (2004). Benjamin Franklin: Papers onElectricity, pp. 276–277, http://www.franklinpapers.org.

[11] Labaree, L.W. et al. The Papers of Benjamin Franklin,Yale University Press, New Haven, Vol. 10, p. 52,http://www.franklinpapers.org.

[12] (1978). Encyclopaedia Britannica, Encyclopedia Britan-nica, Inc., 15th edition, Vol. 6, p. 537, ISBN:0-85229-330-5.

[13] (2008). http://enwikipedia.org/wiki/History of electricalengineering, p. 2.

[14] (2008). Edison Papers, http://edison.rutgers.edu/images/fa/fa0631.jpg.

[15] ANSI C2-1981, National Electrical Safety Code, (1981).Edition, Section 381-G, p. 304.

[16] (2008). http://www.wiretron.com.[17] National Fire Prevention Association (2005). Standard

70 National Electrical Code, pp. 27, 34, 81.

THOMAS P. SHEFCHICK