ELECTRICAL FIRE OUTBREAKS IN HOMES: causes and solutions

By

Engr H. E. Orovwode. (MNSE, REngr)

Electrical and Information Engineering Department, College of Science and Technology,

CovenantUniversity, Ota, Ogun State, Nigeria.

(E-mail: )

Abstract

If the full benefit of the deregulation is to be enjoyed, standards have to be maintained in utilization of electrical power. The rate of fire outbreaks in Nigeria and other parts of the world in recent times is assuming a threatening proportion. Most of which are attributed to electrical faults. Properties worth millions of Naira and many lives are lost annually to this sinister of fire. This paper , therefore, x- rays the causes of electrical fire to include heat from poor connections and glowing connection, short circuit,incorrectly installed wiring ,overloaded circuits and extension cords; Improper plugs, switches and outlets; misuse and poor maintenance of lighting; lack of proper protection and earthing system. This problem, however, can be greatly reduced or eliminated by adequate orientation on the part of consumers, proper installation practice, effective cable selection and rating as well as installation of sensitive protective equipment and early fire warning devices. This paper will be of great relevance to individuals, institutions, power utility providers and government orientation and regulation agencies.

Keywords: heat, fire, safety, protection, prevention

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1.0 Introduction:

You need to understand and respect the power of electricity and the role it can play in home fires.

If the full benefit of the deregulation is to be enjoyed, standards have to be maintained in utilization of electrical power.

It can start in an instant and consume your home in just minutes. It takes lives, injures victims, destroys homes, and steals precious possessions. Fire can harm all of us [5]

1.1 How fire burns Fire requires three elements, both to ignite and to continue burning: They are

Heat: Common heat sources include a hot stove burner, a spark from a worn electrical wire

. Fuel: Just about everything in your home can fuel a fire — clothing, food, furniture, clutter, paper, plastics and more.

Oxygen: The oxygen in the air around us also fuels a fire. As a fire burns, the heat it creates warms nearby items, making it even easier for them to start burning, too. The bigger the fire gets, the more quickly it spreads. In less than 30 seconds, a small flame can turn into a major blaze.

Electric currents (I) carried by wiring, switches, plugs and appliances generate heat .The quantity of heat generated being a function of the resistance (R) of the load is given as I2R (1)

Excessive or uncontrolled heat can start fires.

Properties and valuables worth millions of naira and a lot of lives are being lost annually to electrical related fire. Though accurate statistics are not available in Nigeria, however, in Benin City (EdoState) alone, not less than five houses were raised down by fire between September and December 2006 whose causes were linked directly or indirectly to electrical faults

Thisday newspaper headquarters in Lagos, the asset declaration unit of the code of conduct bureau in Abuja, Chevron headquarters in Lagos and the medical laboratory in Katsina GeneralHospital in KatsinaState were not spared by fire recently.

Consider these startling statistics: In the United States of America, there is a home-fire injury every 23 minutes. A home-fire death happens every 130 minutes. In 2000 alone, 3,420 people died in home fires one of the highest fire death rates among industrialized nations. [7]

Japan has approximately 60000 fires a year. The number of fires related to electricalcause or electrical appliances are shown in table 1 [1,2]

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Table 1 Statistics of electrical fires in Japan

Year / 1980 / 1981 / 1982 / 1983 / 1984 / 1985
Total number of fires / 59885 / 59865 / 63272 / 58833 / 59674 / 55763
Electric heater for cooking / 192 / 193 / 155 / 176 / 190
Electric room heater / 363 / 457 / 539 / 511 / 637 / 503
Cable for lighting or telephone / 800 / 881 / 930 / 944 / 972 / 978
Electrical equipments / 502 / 445 / 471 / 447 / 453 / 489
Electrical appliances / 819 / 713
Wiring devices / 398 / 459 / 468 / 450 / 428 / 507
Light including neon light / 358 / 321 / 331 / 310
Electric Iron / 130 / 128 / 94 / 98
Others / 1659 / 1564 / 1582 / 1590

Note: Blank is due to the change of classification. (Source: Japanese report on Electrical fire cause (1996))

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1.2 Effects of Electrical fire:

  • ElectricalFire Creates Poisonous Smoke: Smoke and poisonous gases spread quickly from where the fire begins and can overwhelm you long before you see any flames. Two common deadly gases in home fires are: Carbon monoxide — displaces oxygen from the blood and Carbon dioxide — causes people to breathe more quickly and inhale more poisonous gas.
  • ElectricalFire Creates Intense Heat: In the first few minutes of a home fire, room temperature can reach 100ºF at floor level and 600ºF at eye level. This intense heat can cause serious injuries and death:
  • ElectricalFire Creates Emotional Trauma: In addition to the physical dangers, fire takes a tremendous emotional toll on people and their families. Losing one's home and treasured possessions is traumatic. Belongings collected throughout your lifetime or handed down for generations are impossible to replace.

1.3 Causes of electrical fire: The chief culprits in most electrical fires are:

  • Incorrectly installed wiring. Any electrical installation that is not well planned, designed and installed poses a great danger for the end user. Installation done without regards to IEE regulations and proper cable sizing by unqualified and unlicensed Electricians is a risk. Many homes and offices have been raised down by fire resulting from installations carried out by “let there be light” Electricians
  • Overloaded circuits and extension cords. Most users of electrical circuits and extension cords plug any load without considering its capacity. It should be noted that every circuit is connected with cable and every cable has its current carrying capacity. Therefore, loading any circuit above its capacity means inviting trouble.
  • Improper plugs, switches and outlets. The use of improper plugs that does not fit to sockets, switches that are under rated and indiscriminate connection of power outlets through unsafe (where there are inflammable materials like rug, carpet, etc) areas causes short circuits and the consequent fire.
  • Misuse and poor maintenance of lighting: Every lighting point has its capacity. The practice in some areas (especially places where there are regular voltage drops) is plugging 200W incandescent bulb in 60W lamp holders in other to solve poor illumination problem. Some consumers even connect socket extension to lighting point. It should be noted that lighting point connection is usually at the ceiling which have some inflammable materials that can burst into flame when excessive heat is generated around them. Poor illumination problem can be solved using automatic voltage regulators (AVRs) [Usifo, (2006)].
  • Glowing connectionand heat from poor connections:A series of experiments has been carried out to study the phenomenon of glow at thecontacts of copper-to copper as well as copper - to- other metals and its link to electrical fire. In these experiments, the contacts of copper wires connected to AC or DCpower source and a variable load resistance in series were used. The results show that Iron starts glowing more easily than copper or brass. But the electrical energy dissipated at the glowing copper oxide or brass oxide is larger than that dissipated at the glowing iron oxide [1].This phenomena can hardly be found until a fire starts because the voltage drop at the contact is only several Volts and most electrical appliances are not affected by it. Small current (AC 0.5A) can start this phenomena and the maximum temperature atthe glow, although which is very small, will exceed 1000o C. This could lead to fire outbreak. A very conspicuous place where this phenomenon is observable is the cut-out fuse point which is usually mounted on wooden board where aluminum cables from service lines are connected with copper used in the house installation and it is located close to the ceiling in most cases. It can be noticed that contacts around this area are always charred.
  • short circuit : shot circuit arising from usage of faulty and old appliances, cables with worn-out or partially broken insulation can causes fire especially when installation lacks sensitive and effective
  • Lack of proper protection and earthing system. Many consumers look at the cost of installing protective facilities as a waste since its function is not evident on daily basis. Those who manage to install at the beginning do not bother to repair or replace them when they are faulty. When duty calls they will definitely fail you.

1.4 Safety tips for Electrical fire prevention: In view of the above discussions, the following safety tips are suggested: 1. Proper orientation: Have a just-in-case plan. Make sure your kids know what to do if the fire alarm goes off. They should hold hands and stay together, and one parent should be in charge of leading them out to a safe place. They should know how to get in formation and follow orders, even when half asleep.. You should keep a strong flashlight by your bed in case your power fails, as it often will during a fire. Rehearse your escape plan several times a year. Know how to get out. If you are upstairs and the fire gets to your stairway before you do, you could be in serious trouble if you don’t have an escape plan. Be sure all your windows open easily, and keep some escape ladders in your upper floors. Make sure both spouses and older children know how to unfold, safely attach, and use the ladders. Practice escaping from any upper floors of the house a few times a year. Be sure that all your fire extinguishers will work for wood, chemical, and electrical fires because not all brands do. Make sure both spouses and all older children know how to use the fire extinguishers.

Educate all in your house never to leave anything that could catch fire near a heat source, like an oven, a radiator, or a portable and switch off any gadget that is not in use before leaving the house.

1.5. Warning Signs: The following warning signs [4] may indicate electrical problems that could cause a fire. If you experience any of these warning signs in your home, contact a licensed electrician to repair the problem:

  • Flickering or dimming lights.
  • Switches or outlets that are hot to the touch or emit an acrid odor.
  • Discolored cords, outlets and switchplates.
  • Repeated blowing of fuses or tripped circuit breakers.

Employ the services of a qualified and licensed engineer and/or electrician to:

  • To design and install all electrical services in your home and offices
  • Inspect a home and make any needed repairs anytime the need arises.
  • Ensure that any electrical modifications meet existing codes.
  • Inspect and repair outlets and switches.
  • Earth the installation and regularly check its efficacy.

1.6In the case of Fuses and Circuit Breakers,

  • Be sure to replace fuses or circuit breakers with ones of the correct size. Cords, Outlets and Plugs [4] Be safety conscious by taking these precautions when using plugs and electrical cords:
  • Don't run cords under carpeting, bedding or other combustible materials, or across doorways or frequently traveled areas.
  • Discard frayed or broken cords and never splice two cords together.
  • Don't overload outlets or use extension cords in place of outlets because these unsafe methods create too much heat and can easily cause fires. Call an electrician to install additional outlets as necessary.
  • Be sure plugs fit snugly in outlets to prevent shock and excess heat.
  • Don’t use two pin plugs for connecting any appliance that has metallic enclosure

For lightings, Combustible materials can ignite easily when they are exposed to hot bulbs. Keep the following tips in mind when using light fixtures:

  • Purchase quality lamps and fixtures listed with Underwriters Laboratories (UL), an independent, not-for-profit safety testing and certification organization.
  • Use the right bulb wattage for all lamps and fixtures.
  • Position lamps away from open windows where strong breezes can blow draperies onto hot light bulbs.

3. Installation of fire early warning devices like fire alarms and detectors: [3]

A fire alarm is a control device that detects and reports fire. Keep your fire alarms in working order. Make sure you have working fire alarms on every floor of the house especially the kitchen and near your bedroom because most fatal home fires begin in one room and kill people in other rooms only after the fire
has reached extremely high temperatures in the room of fire origin and the fire spreads to
other rooms of the house. These fires are readily detected by all common types of smokedetectors in time for sleeping occupants to be awakened and escape.. You should change the batteries twice a year. Don’t ever turn off or remove your fire alarms for any reason. People most often do this when they’re cooking and creating a lot of smoke that fire alarm can get annoying when it keeps going off while you are trying to cook. Don’t smash the alarm to turn them off It is easy to forget to turn it back on. Instead, open the windows and turn on the kitchen fan before you start cooking. It’s also best not to trust that your fire alarms work, even if they have fresh batteries always test them by lighting a match underneath

4. Use of fire proof safe: It is extremely important never to run back into a burning building, for any reason it could be a death sentence. If there is something you really don’t want to lose like valuable documents or jewelry, buy a fireproof safe or cabinet to keep it in. That way, you won’t worry about leaving something important inside the house, and you won’t be tempted to run back in especially if the fire doesn’t look that bad yet. Even if it doesn’t look that bad, it can still kill you. Keeping your most important belongings in a fireproof safe or cabinet could save your life.

Conclusion: This paper has looked into the problems of fire, effects of fire and causes of electrical fire which include heat from poor connections and glowinging connection, short circuit, incorrectly installed wiring, overloaded circuits and extension cords; Improper plugs, switches and outlets; misuse and poor maintenance of lighting; lack of proper protection and earthing system. This paper, also, had suggested that this problem can be greatly reduced or eliminated by adequate orientation and imbibing good safety culture on the part of consumers, proper installation practice, effective cable selection and rating on the part of designers and utility providers as well as installation of sensitive protective equipment and early fire warning devices. Standards have to be maintained in utilization of electrical power if the full benefit of the deregulation is to be enjoyed,

References:

[1] Hagimoto, Y (1996) “Fire Hazards of Wiring and Wiring Devices” Summary of Annual Meeting of Japan Society for Safety Engineering (JAFSE) (March 1996) pg 10

[2] Hagimoto, Y., Watanabe, N., Kinoshita K.; (1996) “Fire Hazard of Short Circuits on Electrical Wiring”Summary of Annual Meeting of Japan Society for Safety Engineering (JAFSE) (March 1996) pgs 13-15

[3] com/smoke_detectors.html (retrieved on Sunday 20th January, 2006)

[4] (retrieved on Sunday 20th January, 2006)

[5] .htm(retrieved on Sunday 20th January, 2006)

[6] Usifo, F. O. (2006) “poor illumination at home for electricity users, causes and solutions”; paper presented at the international conference on Engineering Research and Development, University of Benin , Benin city, Nigeria; September, 2006.

[7] US department of commerce, fire investigation handbook (2002) (NBS handbook), US, GPO.

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