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BC Class B Electrical FSR study materials
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BC Class B Electrical FSR practice questions

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Question 1Electrical code and installation requirements

In the Canadian Electrical Code, what is the primary purpose of bonding metal parts that are not intended to carry current?

  1. To ensure that fault current has a low-impedance path back to the source so overcurrent devices operate Correct answer.
  2. To provide a return path for normal load current during balanced operation
  3. To reduce the resistance of the earth electrode so lightning is safely dissipated
  4. To lower the voltage drop experienced by equipment at the end of a long branch circuit

Explanation

Bonding provides an intentional low-impedance path that allows fault current to return to the supply source, so the overcurrent protective device opens quickly and limits touch voltage on metal parts. It is not intended to carry normal load current or to improve lightning dissipation.

Question 2Electrical code and installation requirements

Which conductor in a typical residential service is connected to the earth electrode and to the panel enclosure?

  1. The grounding conductor Correct answer.
  2. The neutral (identified) conductor is never connected to the enclosure
  3. The equipment grounding conductor of branch circuits only
  4. The ungrounded (hot) conductors

Explanation

The grounding conductor ties the service equipment enclosure and the neutral point to the earth electrode at the service, establishing the reference to ground. Ungrounded conductors carry load current and are never intentionally connected to the enclosure.

Question 3Electrical code and installation requirements

What is the minimum number of receptacle outlets required on a 20 A branch circuit in a kitchen counter area of a dwelling, according to general spacing practice for small-appliance circuits?

  1. At least one small-appliance branch circuit is required
  2. At least four small-appliance branch circuits are required
  3. At least two small-appliance branch circuits are required Correct answer.
  4. At least three small-appliance branch circuits are required

Explanation

Dwelling units require a minimum of two 20 A small-appliance branch circuits to supply kitchen counter receptacles. These circuits may also supply other specified areas but must not serve lighting outlets.

Question 4Electrical code and installation requirements

Which of the following best describes the function of a ground fault circuit interrupter (GFCI)?

  1. It limits the total load current to the rating of the branch circuit
  2. It opens the circuit when current leaks to ground exceeds a small threshold Correct answer.
  3. It disconnects the circuit when the equipment grounding conductor is energized by a short
  4. It reduces the voltage supplied to wet locations to a safe level

Explanation

A GFCI compares current in the ungrounded and grounded conductors and trips when the imbalance indicates leakage to ground, protecting people from shock. It does not limit normal load current or reduce voltage.

Question 5Electrical code and installation requirements

For a 120 V branch circuit supplying a 12 A continuous load, which overcurrent device rating is the minimum standard size permitted?

  1. 30 A
  2. 10 A
  3. 15 A
  4. 20 A Correct answer.

Explanation

Continuous loads must be sized at 125 percent of the load current, so 12 A becomes 15 A, and the next standard rating that is not smaller is 20 A when 15 A is exceeded by the calculation. Applying the 125 percent factor: 12 × 1.25 = 15 A, and the standard 15 A device is acceptable only if the load does not exceed 80 percent continuously; 15 A × 0.8 = 12 A, so a 15 A device is actually adequate. The minimum standard rating that carries the continuous load is therefore the smallest standard size not less than the calculated value.

Question 6Electrical code and installation requirements

A conductor must be protected against overcurrent in accordance with its ampacity. Which condition allows the next larger standard overcurrent device to be used?

  1. When the load is continuous and the conductor is copper
  2. When the conductor is installed in a raceway
  3. When the ambient temperature is below 30 degrees Celsius
  4. When the conductor ampacity does not correspond to a standard device rating and the next size up does not exceed the conductor ampacity by more than the permitted percentage Correct answer.

Explanation

Where the ampacity of a conductor does not match a standard fuse or breaker rating, the next higher standard rating may be used provided it does not exceed the conductor ampacity by more than the percentage the code permits, and the load does not exceed the conductor ampacity. This rule prevents nuisance tripping while keeping the conductor protected.

Question 7Electrical code and installation requirements

Which of the following installations requires a bonding jumper to be sized in accordance with the supply conductor size rather than the equipment grounding conductor table?

  1. Bonding a luminaire to a box
  2. Bonding the metal water piping system to the service enclosure Correct answer.
  3. Bonding a panelboard enclosure to the neutral bus
  4. Bonding a metal raceway at a junction box

Explanation

Bonding of metallic water piping systems is sized using the table based on the largest ungrounded service conductor, because it must carry fault current comparable to the service conductors. Small bonding jumpers in boxes and luminaires use the equipment grounding conductor sizing rules.

Question 8Electrical code and installation requirements

What is the purpose of the grounding electrode system at a building?

  1. To carry unbalanced neutral current back to the utility
  2. To limit voltage surges and provide a reference potential to earth Correct answer.
  3. To clear ground faults in branch circuits
  4. To replace the equipment grounding conductor in feeders

Explanation

The grounding electrode system provides a connection to earth that stabilizes voltage during surges and lightning and establishes a reference potential. It is not the primary path for clearing faults, which is the bonding path.

Question 9Electrical code and installation requirements

In a dwelling unit, a receptacle is installed within 1.5 m of a kitchen sink. What protection is generally required?

  1. Ground fault circuit interrupter protection Correct answer.
  2. Arc fault circuit interrupter protection only
  3. A weatherproof cover
  4. No special protection is required

Explanation

Receptacles near sinks in dwelling units require ground fault circuit interrupter protection to reduce shock risk in wet locations. AFCI protection addresses arc faults and does not substitute for GFCI in wet areas.

Question 10Electrical code and installation requirements

What is the minimum burial depth for direct-buried nonmetallic-sheathed cable supplying a dwelling, where no other protection is provided?

  1. 600 mm
  2. 450 mm Correct answer.
  3. 300 mm
  4. 900 mm

Explanation

Direct-buried cable for residential branch circuits requires a minimum cover of 450 mm unless additional protection such as a raceway or concrete is provided. Greater depths apply to other wiring methods and voltages.

Question 11Electrical code and installation requirements

A 240 V, single-phase feeder supplies a 9 kW load. What is the approximate current drawn by the load?

  1. 75 A
  2. 18.75 A
  3. 9 A
  4. 37.5 A Correct answer.

Explanation

Current equals power divided by voltage, so 9000 W divided by 240 V equals 37.5 A. This current is then used to select conductor ampacity and overcurrent protection.

Question 12Electrical code and installation requirements

Which of the following is required for a conductor used as an equipment grounding conductor in a flexible cord?

  1. It must be bare copper only
  2. It must be insulated and colored green or green with yellow stripes Correct answer.
  3. It must be the same size as the ungrounded conductors regardless of ampacity
  4. It must be connected to the neutral terminal

Explanation

Equipment grounding conductors in flexible cords are identified by a green or green-with-yellow-stripe insulation and must be insulated in cords. They are connected to the equipment enclosure and grounding pin, never to the neutral terminal.

Question 13Electrical code and installation requirements

What is the primary purpose of arc fault circuit interrupter protection in dwelling unit branch circuits?

  1. To detect and interrupt series and parallel arcing that could ignite combustible materials Correct answer.
  2. To protect people from electric shock in wet locations
  3. To limit the available fault current at the panel
  4. To prevent overvoltage from utility switching

Explanation

An AFCI monitors the circuit waveform for characteristics of arcing and opens the circuit to reduce the risk of fire from damaged or loose conductors. It does not provide shock protection like a GFCI or limit fault current.

Question 14Electrical code and installation requirements

A junction box contains 6 current-carrying conductors and is used for a 3-phase, 4-wire feeder. Which factor applies to conductor ampacity adjustment for the number of current-carrying conductors in a raceway?

  1. No adjustment is required for fewer than 3 conductors
  2. Adjustment applies only to conductors larger than 6 AWG
  3. Adjustment is required only for aluminum conductors
  4. Adjustment begins when more than 3 current-carrying conductors are installed together Correct answer.

Explanation

Ampacity adjustment for bundling applies when more than three current-carrying conductors are installed in a raceway or cable, with factors decreasing as the count rises. The neutral may or may not count depending on the circuit type and harmonic content.

Question 15Electrical code and installation requirements

Which statement correctly describes the requirement for bonding at a separately derived system?

  1. The grounded conductor must be bonded to the equipment enclosure at the source of the separately derived system Correct answer.
  2. The bonding must be made only through the earth electrode
  3. The bonding must occur at the farthest outlet
  4. The grounded conductor must never be bonded at a separately derived system

Explanation

At a separately derived system, the grounded conductor is bonded to the equipment enclosure and grounding electrode at the source, establishing the system grounding point. Additional downstream bonds would create parallel neutral paths.

Question 16Electrical code and installation requirements

A 3-phase, 4-wire feeder supplies nonlinear loads with significant harmonic content. How is the neutral conductor treated for ampacity adjustment purposes?

  1. It is never counted as a current-carrying conductor
  2. It is counted only if it is larger than the phase conductors
  3. It must be counted as a current-carrying conductor Correct answer.
  4. It may be omitted from the feeder

Explanation

When a feeder supplies nonlinear loads with harmonic currents, the neutral can carry substantial current, so it is counted as a current-carrying conductor for ampacity adjustment. This prevents overheating of the neutral in shared raceways.

Question 17Electrical code and installation requirements

What is the required working clearance in front of a panelboard with exposed live parts on one side and no grounded parts on the other, for equipment operating at 120/240 V?

  1. 1000 mm
  2. 900 mm Correct answer.
  3. 750 mm
  4. 1500 mm

Explanation

For equipment operating at 120/240 V with exposed live parts on one side and no live or grounded parts on the other, the minimum working clearance is 900 mm. Clearances increase with voltage and with grounded parts opposite.

Question 18Electrical code and installation requirements

Which of the following best describes the requirement for a disconnecting means at a building supplied by a feeder?

  1. The disconnecting means must be located within the meter base
  2. No disconnecting means is required if the panel has a main breaker
  3. A disconnecting means is required only at the utility pole
  4. A disconnecting means must be provided at the point of entry and must be capable of being locked open Correct answer.

Explanation

A building supplied by a feeder requires a readily accessible disconnecting means at the point of entry that can be locked in the open position for maintenance. This allows the supply to be isolated independently of the utility.

Question 19Electrical code and installation requirements

A motor branch circuit has a full-load current of 20 A. What is the maximum rating of the inverse-time circuit breaker permitted for short-circuit and ground-fault protection, using the standard 250 percent allowance?

  1. 30 A
  2. 60 A
  3. 50 A Correct answer.
  4. 40 A

Explanation

Inverse-time breakers for motor branch-circuit short-circuit protection may be rated up to 250 percent of the motor full-load current, so 20 A times 2.5 equals 50 A. If that rating does not allow the motor to start, the next standard size may be used.

Question 20Electrical code and installation requirements

Which of the following is a correct requirement for receptacle outlets in a bathroom of a dwelling unit?

  1. Receptacles require no GFCI protection if they are more than 1 m from the sink
  2. Receptacles must be supplied by a dedicated 15 A circuit
  3. Receptacles may be supplied by a general-purpose circuit shared with other rooms if GFCI protected
  4. Receptacles must be GFCI protected and supplied by a 20 A branch circuit that serves only the bathroom Correct answer.

Explanation

Bathroom receptacles in dwelling units require GFCI protection and must be supplied by a 20 A branch circuit that does not serve outlets outside the bathroom. This prevents overloads and shock hazards in wet areas.

Question 21Electrical code and installation requirements

What does the term "readily accessible" mean when applied to electrical equipment?

  1. Located within sight of the panelboard
  2. Requiring the use of a ladder to reach
  3. Accessible only to qualified persons with a key
  4. Capable of being reached quickly for operation without climbing over or removing obstacles Correct answer.

Explanation

Readily accessible means the equipment can be reached quickly for operation, renewal, or inspection without requiring a person to climb over or remove obstacles or resort to portable ladders. It does not mean locked or within sight.

Question 22Electrical code and installation requirements

A conductor is installed in an ambient temperature of 40 degrees Celsius. What must be considered when selecting its ampacity?

  1. The conductor must be derated only if it is aluminum
  2. The ampacity must be corrected using the ambient temperature correction factor Correct answer.
  3. The conductor ampacity increases with higher ambient temperature
  4. No correction is needed because ampacity tables assume 40 degrees Celsius

Explanation

Ampacity tables are based on a reference ambient temperature, and where the actual ambient is higher, a correction factor must be applied to reduce the ampacity. Higher ambient temperature reduces the conductor's ability to dissipate heat.

Question 23Electrical code and installation requirements

Which of the following is required when installing a grounding electrode conductor to a metal water pipe used as an electrode?

  1. The connection must be made only at the water heater
  2. The connection must be made using solder only
  3. The connection must be made within 1.5 m of the point where the pipe enters the building and must not rely on a removable section Correct answer.
  4. The connection may be made anywhere on the piping system

Explanation

The grounding electrode connection to a metal water pipe must be made within 1.5 m of the pipe's entry into the building and must be ahead of any removable fittings, so the electrode remains connected. The connection must be listed and suitable for the purpose.

Question 24Electrical code and installation requirements

What is the purpose of installing a bonding conductor around a water meter?

  1. To reduce the voltage of the water supply
  2. To provide a return path for neutral current
  3. To maintain electrical continuity of the piping system when the meter is removed Correct answer.
  4. To increase the water pressure in the system

Explanation

A bonding jumper around a water meter ensures the metallic piping remains electrically continuous even if the meter is removed for service, preserving the grounding and bonding path. It has nothing to do with water pressure or neutral current.

Question 25Electrical code and installation requirements

A feeder supplies a subpanel in a detached garage. Which of the following describes the correct treatment of the grounded conductor and equipment grounding conductor at the subpanel?

  1. The grounded conductor and equipment grounding conductor must be separated, with the enclosure bonded to the equipment grounding conductor Correct answer.
  2. The grounded conductor must be omitted
  3. The grounded conductor must be bonded to the enclosure at the subpanel
  4. The equipment grounding conductor must be connected to the neutral bus

Explanation

At a subpanel, the grounded conductor and equipment grounding conductor must be kept separate, and the enclosure is bonded to the equipment grounding conductor. Bonding the neutral at the subpanel would create a parallel return path and is prohibited.

Question 26Electrical code and installation requirements

Which organization publishes the Canadian Electrical Code, Part I, which forms the primary basis for electrical installation requirements in British Columbia?

  1. Electrical Safety Authority
  2. National Fire Protection Association
  3. Canadian Standards Association Correct answer.
  4. Underwriters Laboratories of Canada

Explanation

The Canadian Electrical Code, Part I is a CSA Group standard, adopted in British Columbia through provincial regulation. It sets the minimum installation rules enforced by the provincial safety authority. The other bodies publish different standards or administer enforcement rather than authoring the code itself.

Question 27Electrical code and installation requirements

In British Columbia, which document provides the legal authority for adopting the Canadian Electrical Code and for requiring electrical work to be done under permit?

  1. The provincial electrical safety regulation made under the Safety Standards Act Correct answer.
  2. The utility's terms and conditions of service
  3. The municipal building permit issued by the local government
  4. The manufacturer's installation instructions shipped with the equipment

Explanation

Electrical work in British Columbia is governed by the Safety Standards Act and its electrical safety regulation, which adopt the code and establish permit and inspection requirements. Municipal building permits and utility service conditions address other concerns and do not replace the electrical regulation. Manufacturer instructions must still be followed but are not the legal adoption instrument.

Question 28Electrical code and installation requirements

A feeder is installed using copper conductors and the overcurrent device is rated 100 A. Which conductor size is the minimum generally permitted for a 75 degrees Celsius rated copper conductor under the ampacity tables?

  1. 6 AWG
  2. 8 AWG
  3. 3 AWG Correct answer.
  4. 4 AWG

Explanation

A 75 degrees Celsius copper conductor must have an ampacity of at least 100 A to be protected by a 100 A device. In the standard ampacity table, 3 AWG copper at 75 degrees Celsius is rated 100 A, while 4 AWG is rated only 85 A. Therefore 3 AWG is the smallest size that satisfies the requirement.

Question 29Electrical code and installation requirements

What is the primary function of a bonding conductor connected between non-current-carrying metal parts of equipment?

  1. To balance the load between the phases of a three-phase system
  2. To provide a low-impedance path that lets fault current trip the overcurrent device Correct answer.
  3. To reduce the voltage drop on the circuit during normal operation
  4. To carry the normal operating current of the connected load

Explanation

Bonding creates a low-impedance path back to the source so that a ground fault produces enough current to operate the overcurrent protective device promptly. This limits the duration of dangerous touch voltage on metal parts. Bonding conductors are not intended to carry load current during normal operation.

Question 30Electrical code and installation requirements

A receptacle outlet is installed outdoors on a dwelling unit and is not readily accessible. Which protection is required for this outlet?

  1. A local disconnecting means within sight
  2. Ground fault circuit interrupter protection Correct answer.
  3. An isolated grounding conductor
  4. Arc fault circuit interrupter protection only

Explanation

Outdoor receptacles at dwelling units require ground fault circuit interrupter protection because of the increased shock hazard from wet conditions and contact with earth. The requirement applies whether or not the outlet is readily accessible. Arc fault protection addresses a different hazard and does not replace GFCI protection.

Question 31Electrical code and installation requirements

A panelboard is installed in a hallway. What is the minimum clear working space required in front of the panel where live parts are exposed on one side and no grounded or live parts are on the opposite side?

  1. 1.5 m
  2. 0.5 m
  3. 0.75 m
  4. 1 m Correct answer.

Explanation

The code requires a minimum working space of 1 m in front of electrical equipment operating at up to 150 volts to ground where live parts are exposed on one side only. This clearance permits safe inspection and maintenance. Greater depths apply where equipment faces equipment or where higher voltages are involved.

Question 32Electrical code and installation requirements

A 120 V branch circuit supplies a continuous load of 12 A. What is the minimum overcurrent device rating permitted, applying the continuous-load rule?

  1. 30 A
  2. 20 A Correct answer.
  3. 25 A
  4. 15 A

Explanation

Continuous loads must be sized at 125 percent of the load, so 12 A becomes 15 A. The next standard overcurrent device rating at or above that value is 20 A when a 15 A device is not used, and a 20 A circuit is the common minimum for this load. The conductor must also have adequate ampacity for the device rating.

Question 33Electrical code and installation requirements

Which of the following best describes the requirement for a disconnecting means for a building supplied by a feeder?

  1. A disconnecting means is optional if the panelboard main breaker is lockable
  2. A disconnecting means must be provided at the building, installed in a readily accessible location, and marked to identify the supply Correct answer.
  3. A disconnecting means is required only at the utility service point
  4. A disconnecting means is required only where the building exceeds three storeys

Explanation

Where a building is supplied by a feeder, a disconnecting means must be installed at the building in a readily accessible location and must be permanently marked to indicate the source of supply. This allows responders and maintenance staff to isolate the building. The requirement does not depend on building height or on lockability of a panel main.

Question 34Electrical code and installation requirements

Which of the following is required when a grounding electrode conductor is connected to a metal water pipe used as a grounding electrode?

  1. The connection may depend on a dielectric union for isolation
  2. The connection must be made at the water heater outlet
  3. The connection may be made anywhere on the piping system inside the building
  4. The connection must be made within the first 1.5 m of pipe entering the building and must not rely on a removable fitting Correct answer.

Explanation

The grounding electrode conductor must connect to the metal water pipe within the first 1.5 m after it enters the building, before any removable fitting or equipment. The connection must be made with an approved clamp and must not depend on a union or similar removable fitting. This ensures a reliable, low-impedance electrode connection.

Question 35Electrical code and installation requirements

Why is a bonding conductor installed around a water meter in a metal water piping system?

  1. To increase the water pressure in the piping system
  2. To isolate the piping from the electrical system
  3. To maintain electrical continuity across a removable component that could otherwise interrupt the path Correct answer.
  4. To provide a grounding electrode for the service

Explanation

Water meters are removable and may contain nonmetallic components, so a bonding jumper is installed around the meter to preserve metallic continuity of the piping. This keeps the piping electrically continuous for grounding and bonding purposes. The jumper has no effect on water pressure or on isolating the piping.

Question 36Electrical code and installation requirements

A 3-phase, 4-wire feeder supplies a panelboard with significant nonlinear loads. How must the neutral conductor be sized?

  1. It may have to be larger than the phase conductors because of triplen harmonic currents adding in the neutral Correct answer.
  2. It may always be reduced to 50 percent of the phase conductor ampacity
  3. It must be exactly the same size as the phase conductors in all cases
  4. It may be omitted entirely if the loads are balanced

Explanation

Triplen harmonics from nonlinear loads add in the neutral rather than cancelling, so the neutral current can exceed the phase current. The neutral must therefore be sized to carry the calculated neutral load, which may require a larger conductor. Simply matching the phase size or reducing it is not sufficient where harmonics are significant.

Question 37Electrical code and installation requirements

A single-phase 240 V load draws 20 A. What is the approximate power consumed by the load, assuming unity power factor?

  1. 2.4 kW
  2. 1.2 kW
  3. 4.8 kW Correct answer.
  4. 9.6 kW

Explanation

Power equals voltage multiplied by current for a resistive load, so 240 V times 20 A equals 4800 W, or 4.8 kW. This relationship is used to convert between load current and capacity when sizing feeders and services. Power factor would reduce the real power if it were less than one.

Question 38Electrical code and installation requirements

A motor branch circuit has a full-load current of 25 A. What is the maximum rating of an inverse-time circuit breaker permitted for short-circuit and ground-fault protection, applying the standard 250 percent allowance?

  1. 60 A Correct answer.
  2. 50 A
  3. 40 A
  4. 70 A

Explanation

Inverse-time breakers for motor branch circuits are generally permitted at up to 250 percent of the motor full-load current. For 25 A, 250 percent is 62.5 A, and the next standard breaker rating not exceeding that value is 60 A. The overload protection is provided separately by the motor overload device.

Question 39Electrical code and installation requirements

What does the term readily accessible mean when applied to electrical equipment?

  1. Reachable only after the main disconnect is opened
  2. Accessible only to qualified persons using special tools
  3. Capable of being reached quickly for operation without climbing over or removing obstacles Correct answer.
  4. Located within sight of the panelboard feeding it

Explanation

Readily accessible means the equipment can be reached quickly for operation, renewal, or inspection without requiring a person to climb over or remove obstacles or resort to portable ladders. It does not mean accessible only to qualified persons or within sight of another item. The concept focuses on unobstructed, quick reach.

Question 40Electrical code and installation requirements

A conductor with 75 degrees Celsius insulation is installed where the ambient temperature is 40 degrees Celsius. What must be done when selecting its ampacity?

  1. The ampacity must be reduced using the correction factor for the higher ambient temperature Correct answer.
  2. The ampacity may be increased because the insulation is rated above the ambient
  3. The ampacity is unaffected because ambient temperature does not apply to insulated conductors
  4. The conductor must be derated only if it carries a continuous load

Explanation

Ampacity tables are based on a reference ambient temperature, so where the actual ambient is higher the conductor ampacity must be reduced by the applicable correction factor. Failing to correct can cause insulation overheating and premature failure. The correction applies regardless of whether the load is continuous.

Question 41Electrical code and installation requirements

A 3-phase, 4-wire feeder supplies a panelboard where the neutral is not required to carry the unbalanced load of line-to-neutral loads. Under what condition may the neutral be sized smaller than the phase conductors?

  1. When the calculated neutral load is less than the phase load and the neutral is sized for that calculated load Correct answer.
  2. When the feeder is installed in a raceway rather than as cable
  3. When the panelboard main breaker is rated above the feeder ampacity
  4. When the phase conductors are oversized for voltage drop

Explanation

The neutral of a feeder may be reduced where the calculated neutral load is smaller than the phase load, provided the neutral is sized for the calculated load and any harmonic considerations are addressed. Oversizing phase conductors for voltage drop or the type of wiring method does not by itself justify a reduced neutral. The neutral must always be adequate for the load it carries.

Question 42Electrical code and installation requirements

Which of the following is required for a receptacle installed in a kitchen counter area of a dwelling unit?

  1. Arc fault circuit interrupter protection only
  2. Ground fault circuit interrupter protection where the receptacle serves the counter surface within the required distance of a sink Correct answer.
  3. An isolated grounding receptacle
  4. A lockable disconnecting means adjacent to the receptacle

Explanation

Receptacles serving kitchen counter surfaces within the specified distance of a sink require ground fault circuit interrupter protection because of the shock hazard from water. This protection is in addition to any other required protection. Isolated grounding and local disconnects are not general requirements for kitchen counter receptacles.

Question 43Electrical code and installation requirements

A service is supplied at 120/240 V single-phase. What is the minimum general lighting load for a dwelling unit of 150 square metres, using the standard 24 VA per square metre allowance?

  1. 1500 VA
  2. 2400 VA
  3. 4800 VA
  4. 3600 VA Correct answer.

Explanation

The general lighting load is calculated by multiplying the floor area by the unit allowance, so 150 square metres times 24 VA per square metre equals 3600 VA. Demand factors may then be applied to this total for service calculations. The other values result from using incorrect areas or allowances.

Question 44Electrical code and installation requirements

Which of the following correctly describes the requirement for bonding at a separately derived system?

  1. The grounded conductor must be isolated from the equipment grounding conductor at the source
  2. Bonding is required only if the system exceeds 600 V
  3. Bonding is required only at the utility transformer
  4. The grounded conductor must be bonded to the equipment grounding conductor at the source and a grounding electrode connection made where required Correct answer.

Explanation

At a separately derived system, the grounded conductor is bonded to the equipment grounding conductor at the source, and a grounding electrode connection is made where required. Downstream of that point the grounded conductor and equipment grounding conductor must be kept separate. This establishes a defined return path for fault current at the source.

Question 45Electrical code and installation requirements

A flexible cord is used to connect a portable appliance. Which of the following is required for the equipment grounding conductor in the cord?

  1. It may be connected to the neutral at the receptacle
  2. It must be identified and must be continuous throughout the cord Correct answer.
  3. It may be smaller than the circuit conductors in all cases
  4. It may be omitted if the appliance is double insulated

Explanation

Where a flexible cord includes an equipment grounding conductor, that conductor must be identified and must run continuously through the cord to the appliance. It must never be connected to the neutral or omitted except where the appliance is specifically designed without one. Its size is governed by the applicable cord table.

Question 46Electrical code and installation requirements

A buried nonmetallic-sheathed cable supplies a dwelling unit where no other protection is provided. What is the minimum cover required?

  1. 300 mm
  2. 600 mm
  3. 150 mm
  4. 450 mm Correct answer.

Explanation

Direct-buried cable without additional protection requires a minimum cover of 450 mm to reduce the risk of damage from digging. Greater depths apply to some other wiring methods and locations. Lesser covers are permitted only where additional protection such as a concrete slab or conduit is provided.

Question 47Electrical code and installation requirements

Which of the following is a correct requirement for a grounding electrode system at a building?

  1. It must be disconnected whenever the service is de-energized
  2. It must be bonded together into a single grounding electrode system where multiple electrodes are present Correct answer.
  3. Each electrode must be connected to a separate grounding electrode conductor run to the panel
  4. It may consist of a single isolated rod without any connection to the service

Explanation

Where more than one grounding electrode is present, the electrodes must be bonded together to form a single grounding electrode system. This reduces impedance and provides a more effective fault-current path. Separate isolated runs and disconnecting the electrode system are not permitted practices.

Question 48Electrical code and installation requirements

A 120/240 V service supplies a dwelling unit. What is the minimum number of 20 A small-appliance branch circuits required for the kitchen, pantry, and dining areas?

  1. Two Correct answer.
  2. Four
  3. One
  4. Three

Explanation

At least two 20 A small-appliance branch circuits must be provided to supply receptacle outlets in the kitchen, pantry, dining room, and similar areas. These circuits may also supply other specified outlets but have restrictions. Additional circuits may be needed based on the load, but the minimum is two.

Question 49Electrical code and installation requirements

A conductor is installed in a raceway where the ambient temperature is 50 degrees Celsius and the conductor insulation is rated 90 degrees Celsius. What must be considered when determining the ampacity?

  1. The conductor may use the 90 degrees Celsius ampacity without correction
  2. The conductor must be replaced with one rated 60 degrees Celsius
  3. The ampacity is determined solely by the overcurrent device rating
  4. The ampacity from the 90 degrees Celsius column must be corrected for the 50 degrees Celsius ambient Correct answer.

Explanation

Ampacity values for a given insulation rating are based on a reference ambient temperature, so a 50 degrees Celsius ambient requires correction even for 90 degrees Celsius insulation. The corrected ampacity must still be adequate for the load and coordinated with the overcurrent device. The insulation rating alone does not eliminate the need for correction.

Question 50Electrical code and installation requirements

Which of the following is required for a receptacle outlet installed in a laundry area of a dwelling unit?

  1. A dedicated 240 V circuit
  2. Ground fault circuit interrupter protection for the receptacle Correct answer.
  3. Arc fault circuit interrupter protection only
  4. An isolated grounding conductor

Explanation

Receptacles in laundry areas of dwelling units require ground fault circuit interrupter protection because of the presence of water and damp conditions. This is in addition to any other required protection. Isolated grounding and dedicated 240 V circuits are not general requirements for laundry receptacles.