← Chapter 39 - Electrical Fires Export Options Alphabetize Word-Def Delimiter Tab Comma Custom Def-Word Delimiter New Line Semicolon Custom Data Copy and paste the text below. It is read-only. Select All Electrical circuit insulation: a) Will never break down or deteriorate b) Requires replacement after 10 years c) Will deteriorate due to high temperatures d) Will not burn c) Will deteriorate due to high temperatures Under the Canadian Electrical Code, if an area contains dust in the air, under normal operation conditions, in concentrations high enough to produce explosive or ignitable mixtures, the electrical equipment must be designed safe for use in an area classification of: a) Class I, Division I b) Class I, Division II c) Class II, Division I d) Class II, Division II c) Class II, Division I Halon from Halon fire extinguishers a) May produce a distinct odour which warns of its presence b) Is abrasive to electrical equipment c) Will act as a conductor if moisture is present d) Is derived from Bromine, Fluorine, or Chlorine a) May produce a distinct odour which warns of its presence A common cause of an electrical fire is: a) Allowing motors or conductors to stay dry, unless designed for wet locations b) Prematurely replacing deteriorated wiring c) Following too closely to the Electrical Code when installing electrical equipment d) Replacing burned fuses with ones of a higher rating d) Replacing burned fuses with ones of a higher rating Halon 1301 presents a hazard for exposures in concentrations above a) 4% b) 15% c) 25% d) 10% d) 10% Which one of the following maintenance procedures is not a concern with preventing fires in electrical equipment? a) Allowing the accumulation of dust on a motor since this buildup will prevent heat from escaping, thus keeping the motor warm in cold ambient conditions b) Keeping electrical equipment dry unless designed for wet locations c) Using the equipment designed for the application d) Checking any aluminum connections frequently for tightness and presence of corrosion a) Allowing the accumulation of dust on a motor since this buildup will prevent heat from escaping, thus keeping the motor warm in cold ambient conditions Electrical connections: A) need only make contact, they need not be tight B) will create large amounts of heat if not tight C) can cause an arc if too tight D) may operate on overload for specified duration E) will not generate heat at any time B) Will create large amounts of heat if not tight When an electrical fire is discovered: A) the equipment may be left running if the fire is put out with a C type fire extinguisher B) the equipment should be de-energized as quickly as possible C) the equipment should be left running until a backup power supply is available D) the equipment may be immediately restarted once the fire is extinguished E) fresh air should be provided to the room as quickly as possible to get rid of toxic fumes B) the equipment should be de-energized as quickly as possible The best type of fire extinguisher to use on a live electrical fire is a: A) pressurized water extinguisher B) dry chemical extinguisher C) purple K extinguisher D) AFFF extinguisher E) carbon dioxide extinguisher E) carbon dioxide extinguisher The temperature of the carbon dioxide leaving the extinguisher horn can be as low as: A) 0 degrees C B) -5 degrees C C) -30 degrees C D) -60 degrees C E) -80 degrees C E) -80 degrees C Halon from halon fire extinguishers: A) produces a distinct odour which warns of the presence of halon B) is abrasive to electrical equipment C) will act as a conductor if moisture is present D) is derived from bromine, fluorine, or chlorine E) is corrosive A) produces a distinct odour which warns of the presence of halon During annual turnaround of a facility it is highly recommended that: A) all fuses in the electrical system be replaced B) aluminium wiring be replaced C) all electrical panels be checked for tightness and corrosion D) all circuit breakers be disassembled and cleaned E) a megger be used on all electric motor windings C) all electrical panels be checked for tightness and corrosion According to the Canadian Electrical Code, hazardous locations, for electrical equipment, are divided into three classes, depending on: A) temperature. B) pressure. C) the type of fire extinguishers available. D) the type of hazardous material involved. E) the capacity of electrical equipment involved. D) the type of hazardous material involved. Dry chemical can form a conducting path to ground if: A) the air is dry. B) any moisture is present. C) it is directed at the base of the flame. D) it is non-conductive. E) it is sprayed over the entire burning area. B) any moisture is present. Switches and circuit breakers which are to be installed in an atmosphere where flammable vapours may continually exist shall be: A) installed in a sealed compartment. B) be explosion proof. C) electrically insulated. D) of an ABSA approved design. E) be made of non-conductive materials. B) be explosion proof.