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C&G 2391-52 practice questions

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Question 1Statutory and non-statutory requirements, BS 7671 and associated guidance

Which statement best describes the legal status of BS 7671?

  1. It is a statutory instrument enforced by the Health and Safety Executive.
  2. It is an approved code of practice issued under the Health and Safety at Work etc. Act 1974.
  3. It is a European Union regulation binding on all member states.
  4. It is a British Standard with no direct statutory force. Correct answer.

Explanation

BS 7671 is a British Standard prepared by the Institution of Engineering and Technology and published by BSI. It is not an Act, regulation or approved code of practice, so it carries no direct statutory force of its own. Compliance is commonly required by contract and is used as evidence of the standard reasonably expected in legal proceedings.

Question 2Statutory and non-statutory requirements, BS 7671 and associated guidance

Which legislation places duties on employers and self-employed persons in respect of electrical systems at work?

  1. The Construction (Design and Management) Regulations 2015
  2. The Supply of Machinery (Safety) Regulations 2008
  3. The Building Regulations 2010
  4. The Electricity at Work Regulations 1989 Correct answer.

Explanation

The Electricity at Work Regulations 1989 impose duties on persons engaged in work activities involving electricity, including employers and self-employed persons, to prevent danger and injury. They apply to all electrical systems used at work irrespective of voltage. The other instruments deal with building work, machinery supply and construction project management respectively.

Question 3Statutory and non-statutory requirements, BS 7671 and associated guidance

In England, which type of work is covered by Part P of the Building Regulations?

  1. Electrical installations in dwellings and associated buildings. Correct answer.
  2. Electrical installations in commercial and industrial premises.
  3. Only the installation of consumer units and final circuits.
  4. Only work carried out by a registered competent person.

Explanation

Part P applies to electrical installations in dwellings, including associated parts such as garages and outbuildings with their own supply, and to certain installations in common areas of buildings containing dwellings. It is not limited to particular items of equipment or to work by registered persons. Commercial and industrial installations fall outside Part P.

Question 4Statutory and non-statutory requirements, BS 7671 and associated guidance

The IET On-Site Guide is best described as:

  1. an approved code of practice under the Health and Safety at Work etc. Act 1974.
  2. a mandatory standard for all installations operating above 1 kV.
  3. a statutory instrument forming part of the Building Regulations.
  4. non-statutory guidance intended to be read with BS 7671. Correct answer.

Explanation

The On-Site Guide is published as practical guidance to accompany BS 7671 and help with the design and installation of typical domestic and small commercial installations. It has no statutory status and does not replace the Regulations themselves. It is not voltage-specific and is not an approved code of practice.

Question 5Statutory and non-statutory requirements, BS 7671 and associated guidance

Which regulations require an employer to report a specified electrical injury sustained by an employee at work?

  1. RIDDOR 2013 Correct answer.
  2. COSHH 2002
  3. PUWER 1998
  4. EAWR 1989

Explanation

The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations require the responsible person to notify the enforcing authority of specified injuries, reportable diseases and dangerous occurrences, including certain electrical incidents. The report is made to the relevant enforcing authority, normally the HSE or the local authority.

Question 6Statutory and non-statutory requirements, BS 7671 and associated guidance

Regulation 4 of the Electricity at Work Regulations 1989 requires that all electrical systems are:

  1. inspected and tested at fixed intervals by a competent person.
  2. replaced once they exceed their design life.
  3. certified by a registered third party before energisation.
  4. constructed and maintained so as to prevent danger. Correct answer.

Explanation

Regulation 4 requires electrical systems to be constructed and maintained so as to prevent danger so far as is reasonably practicable. The Regulations do not impose fixed inspection intervals, third-party certification or a design-life replacement rule. Such practices may be a means of demonstrating compliance but are not the requirement itself.

Question 7Statutory and non-statutory requirements, BS 7671 and associated guidance

Regulation 16 of the Electricity at Work Regulations 1989 is chiefly concerned with which requirement?

  1. Ensuring persons are competent to prevent danger and injury. Correct answer.
  2. The provision of adequate working space and lighting.
  3. The earthing of exposed conductive parts.
  4. The isolation of circuits before work begins.

Explanation

Regulation 16 prohibits engaging a person in work where technical knowledge or experience is necessary to prevent danger, or injury, unless that person possesses such knowledge or experience. Competence must be appropriate to the work and the risks involved. Working space, isolation and earthing are dealt with elsewhere in the Regulations.

Question 8Statutory and non-statutory requirements, BS 7671 and associated guidance

Which HSE publication gives guidance on the Electricity at Work Regulations 1989?

  1. HS(R)25 Memorandum of Guidance Correct answer.
  2. The On-Site Guide
  3. The IET Code of Practice for In-service Inspection and Testing
  4. Guidance Note 3: Inspection and Testing

Explanation

HS(R)25, the Memorandum of Guidance on the Electricity at Work Regulations 1989, is the HSE publication that explains the Regulations and gives practical guidance on compliance. It is not a substitute for the Regulations themselves. The other documents are IET publications relating to BS 7671 or in-service testing.

Question 9Statutory and non-statutory requirements, BS 7671 and associated guidance

A consumer unit in a house in England is to be replaced. What does Part P of the Building Regulations require for this work?

  1. It must be recorded on a minor electrical installation works certificate and copied to the DNO.
  2. It must be reported to the local distribution network operator before the supply is reconnected.
  3. It must be inspected by the Health and Safety Executive before the installation is energised.
  4. It must be notified to building control or be certified under a competent person scheme. Correct answer.

Explanation

Replacing a consumer unit is notifiable work under Part P in England. Compliance is achieved either by notifying the building control body in advance or by using a registered competent person who can self-certify the work. The distribution network operator and the HSE have no such notification role.

Question 10Statutory and non-statutory requirements, BS 7671 and associated guidance

Which regulations require an employer to make a suitable and sufficient assessment of the risks to which employees and others are exposed?

  1. The Provision and Use of Work Equipment Regulations 1998
  2. The Electricity Safety, Quality and Continuity Regulations 2002
  3. The Management of Health and Safety at Work Regulations 1999 Correct answer.
  4. The Building Regulations 2010

Explanation

The Management of Health and Safety at Work Regulations require every employer to make a suitable and sufficient assessment of the risks to employees and to others affected by the undertaking. The assessment then informs the control measures adopted, including those for electrical work. The other instruments deal with work equipment, public supply characteristics and building work.

Question 11Statutory and non-statutory requirements, BS 7671 and associated guidance

Section 3 of the Health and Safety at Work etc. Act 1974 places a duty on employers and self-employed persons towards:

  1. their own employees only.
  2. suppliers of equipment used on site.
  3. persons not in their employment who may be affected. Correct answer.
  4. the enforcing authority.

Explanation

Section 3 requires employers and self-employed persons to conduct their undertaking so that persons not in their employment who may be affected are not exposed to risks to their health and safety. The duty towards employees themselves is set out in section 2. Sections 6 and 7 deal with suppliers and employees respectively.

Question 12Statutory and non-statutory requirements, BS 7671 and associated guidance

Which regulations impose requirements on distributors concerning the characteristics of the public electricity supply, including its earthing arrangements?

  1. The Electricity Safety, Quality and Continuity Regulations 2002, as amended Correct answer.
  2. The Electricity at Work Regulations 1989, as amended
  3. The IET Wiring Regulations, BS 7671, as amended
  4. The Management of Health and Safety at Work Regulations 1999, as amended

Explanation

The Electricity Safety, Quality and Continuity Regulations set requirements on distributors for the safety, quality and continuity of the public supply, including the declared supply characteristics and earthing arrangements. The installer must establish these characteristics before designing an installation. BS 7671 and the other instruments do not impose these duties on distributors.

Question 13Statutory and non-statutory requirements, BS 7671 and associated guidance

BS 7671 is produced under which arrangement?

  1. It is issued by the local distribution network operator.
  2. It is drafted and enforced by the Health and Safety Executive.
  3. It is drafted by the IET and published by BSI as a British Standard. Correct answer.
  4. It is published by the Building Research Establishment.

Explanation

BS 7671, the IET Wiring Regulations, is drafted through the IET's technical committee structure and published by BSI as a British Standard. Its status as a British Standard does not make it statute. Enforcement of electrical safety at work rests with the HSE under the relevant legislation, not with the publishers of BS 7671.

Question 14Statutory and non-statutory requirements, BS 7671 and associated guidance

Regulation 14 of the Electricity at Work Regulations 1989 permits work on or near live conductors only where:

  1. the person carrying out the work holds a current qualification at level 3 or above.
  2. a written permit-to-work has been issued and countersigned by the duty holder.
  3. it is unreasonable in all circumstances for it to be dead. Correct answer.
  4. the nominal voltage of the installation does not exceed 230 volts.

Explanation

Regulation 14 permits live working only where it is unreasonable in all circumstances for the conductor to be dead, it is reasonable in all the circumstances for the work to be carried out live, and suitable precautions are taken to prevent injury. A permit, a voltage threshold or a qualification alone does not satisfy the regulation.

Question 15Statutory and non-statutory requirements, BS 7671 and associated guidance

A statutory requirement conflicts with a recommendation in BS 7671. What is the correct course of action?

  1. Follow BS 7671, because it is the recognised British Standard.
  2. Meet the statutory requirement and, if possible, exceed it. Correct answer.
  3. Refer the matter to the IET before commencing the work.
  4. Follow whichever document was published most recently.

Explanation

Statute takes precedence over a non-statutory standard, so the legal requirement must be met as a minimum. BS 7671 generally aims to be consistent with statutory duties, and exceeding the minimum may be appropriate where risk justifies it. Publication date does not determine legal priority, and no reference to the IET is needed.

Question 16Statutory and non-statutory requirements, BS 7671 and associated guidance

Section 6 of the Health and Safety at Work etc. Act 1974 places duties on whom?

  1. Enforcing authorities inspecting premises
  2. Clients commissioning construction work
  3. Employees who use work equipment
  4. Designers, manufacturers and suppliers of articles for use at work Correct answer.

Explanation

Section 6 requires designers, manufacturers, importers and suppliers of articles and substances for use at work to ensure, so far as is reasonably practicable, that they are safe and without risks to health when properly used. This underpins the safety of equipment before it reaches the installer or user. Duties on employees are in sections 7 and 8.

Question 17Statutory and non-statutory requirements, BS 7671 and associated guidance

The IET Code of Practice for In-service Inspection and Testing of Electrical Equipment is:

  1. a Building Regulations approved document that applies to fixed installations in dwellings.
  2. a statutory code approved by the Health and Safety Executive under section 16 of the Health and Safety at Work etc. Act 1974.
  3. non-statutory guidance on meeting duties under the Electricity at Work Regulations. Correct answer.
  4. a British Standard that must be applied to all portable equipment used in commercial premises.

Explanation

The Code of Practice is industry guidance that describes a risk-based approach to maintaining electrical equipment in a safe condition, supporting compliance with duties such as those in the Electricity at Work Regulations. It does not itself create legal duties and is not an approved code of practice or a British Standard. It also does not form part of the Building Regulations.

Question 18Statutory and non-statutory requirements, BS 7671 and associated guidance

In the context of the Electricity at Work Regulations 1989, 'so far as is reasonably practicable' means that:

  1. the duty holder must eliminate every foreseeable risk regardless of the cost involved.
  2. the duty applies only where the risk arises from equipment operating above 230 volts.
  3. only those risks that are identified in a written risk assessment need to be controlled.
  4. a measure may be omitted where its cost is grossly disproportionate to the risk. Correct answer.

Explanation

Reasonably practicable requires the risk to be weighed against the time, trouble and cost of the measures needed to control it. Where there is gross disproportion between the cost of a measure and the risk it would reduce, the measure is not required. The duty still demands that risk be reduced as far as is sensible, and it applies at all voltages.

Question 19Safe isolation, preparation for inspection and testing, safe working practices

According to guidance on test leads and probes (GS38), what is the recommended maximum length of exposed metal at the tip of a test probe?

  1. 4 mm beyond the finger guard or barrier Correct answer.
  2. 10 mm beyond the finger guard or barrier
  3. 20 mm beyond the finger guard, provided the lead is insulated
  4. There is no limit if the probe is fitted with a fuse

Explanation

GS38 guidance limits exposed metal at a probe tip to 4 mm beyond the finger guard or barrier to reduce the chance of short circuits and arc burns while probing. Longer exposed tips increase the risk of bridging between adjacent live parts.

Question 20Safe isolation, preparation for inspection and testing, safe working practices

Before relying on a voltage indicator to prove a circuit dead, the instrument should be:

  1. Replaced with a new one at the start of every working day
  2. Proved on a known live source or a proving unit Correct answer.
  3. Tested on the circuit being isolated and nowhere else
  4. Checked only by confirming that the display illuminates

Explanation

Proving the indicator on a known source before and after the test confirms that the instrument and its leads are working correctly. This prove–test–prove routine is a core part of safe isolation.

Question 21Safe isolation, preparation for inspection and testing, safe working practices

Which of the following provides the most effective protection against an isolator being switched back on while you are working?

  1. A verbal warning given to everyone on site before work starts
  2. A note left on the consumer unit explaining what is being done
  3. A padlock and warning notice fitted by you Correct answer.
  4. Switching the circuit breaker off at the board

Explanation

A personal padlock whose only key is held by the person working, together with a warning notice, stops others from re-energising the circuit. Simply switching off offers no protection against third parties.

Question 22Safe isolation, preparation for inspection and testing, safe working practices

Which combination of personal protective equipment is most typical as basic protection during general inspection and testing?

  1. Safety footwear, eye protection and insulated gloves where needed Correct answer.
  2. A high-visibility vest, worn at all times on site
  3. A full arc-rated flash suit and insulating mat for every domestic task
  4. Cotton overalls and a soft cap, worn as normal work clothing

Explanation

Basic PPE selected from the risk assessment for routine inspection and testing is normally safety footwear and eye protection, with insulated gloves added where a live or nearby-live hazard exists. Full arc-rated clothing is reserved for higher-risk work identified by assessment.

Question 23Safe isolation, preparation for inspection and testing, safe working practices

Which of the following gives the correct order of steps when safely isolating a single-phase final circuit for testing?

  1. Identify, prove dead, isolate, prove the tester, secure the isolation
  2. Identify, isolate, secure, prove the tester, prove dead, prove the tester again Correct answer.
  3. Prove the tester, isolate, prove dead, secure the isolation, prove the tester again, identify
  4. Isolate, identify, prove dead, secure the isolation, prove the tester once

Explanation

The safe isolation procedure is to identify the circuit, isolate it, secure the isolation (lock off), prove the tester, prove the circuit dead at the point of work, then prove the tester again. Proving dead before isolating, or omitting the final re-prove, breaks the sequence.

Question 24Safe isolation, preparation for inspection and testing, safe working practices

Which instrument is the most appropriate for proving a 230 V single-phase circuit dead?

  1. An approved two-pole voltage indicator with GS38 probes Correct answer.
  2. A non-contact voltage detector held near the conductor
  3. A multimeter set to the highest direct voltage range available
  4. An insulation resistance tester set to 500 V

Explanation

A two-pole voltage indicator designed to the relevant standard gives a definite indication of voltage between two points and loads the circuit slightly. It is the instrument specified for proving dead, whereas non-contact devices can give misleading readings.

Question 25Safe isolation, preparation for inspection and testing, safe working practices

When isolating a single-phase circuit at a consumer unit, which conductors must be isolated before work begins?

  1. The neutral conductor only
  2. The line conductor and the circuit protective conductor
  3. The line conductor only
  4. The line conductor and the neutral conductor Correct answer.

Explanation

Safe isolation requires every live conductor to be isolated, which for a single-phase circuit means both line and neutral. A neutral can be at a potential above earth or can become live if the supply is disturbed.

Question 26Safe isolation, preparation for inspection and testing, safe working practices

A distribution board has no lockable main switch. What is the most appropriate way to secure the isolation?

  1. Tape the switch in the off position
  2. Place a warning notice on the board without fitting any lock
  3. Ask the client to stand by the board and watch it throughout
  4. A lockable fuse carrier or lockable enclosure with a padlock Correct answer.

Explanation

Where the device itself cannot be locked, a proprietary lockable fuse carrier, lockable enclosure or similar device is fitted so a personal padlock can secure the isolation. A warning notice alone does not physically prevent re-energisation.

Question 27Safe isolation, preparation for inspection and testing, safe working practices

What should be done before starting inspection and testing on an unfamiliar installation?

  1. Test live first to identify which circuits are which, then isolate
  2. Switch off the main switch and begin without telling anyone
  3. Carry out a risk assessment and agree the isolation arrangements Correct answer.
  4. Ask the client which circuits are safe and rely on that answer

Explanation

A risk assessment and agreement of the extent of work and isolation arrangements with the person responsible must come before any testing. This establishes what will be isolated, who else may be affected and what precautions are needed.

Question 28Safe isolation, preparation for inspection and testing, safe working practices

Under what conditions may live testing work be carried out?

  1. Whenever the client asks for it, to avoid disruption to their business
  2. Only on single-phase domestic installations below 230 V
  3. Only where working dead is unreasonable, after a risk assessment Correct answer.
  4. Whenever the tester is experienced, without further assessment

Explanation

Live work is permitted only where it is unreasonable to work dead, following a risk assessment and using suitable instruments and precautions. The decision rests on the assessment of risk, not on convenience or the tester's experience.

Question 29Safe isolation, preparation for inspection and testing, safe working practices

When selecting a test instrument for use on the supply side of a consumer unit, which requirement is most relevant?

  1. A CAT II rating on the instrument alone is sufficient for any location
  2. Instrument and leads rated for the overvoltage category of that location Correct answer.
  3. CAT ratings apply only to insulation resistance testers, not indicators
  4. Only the test leads need a rating, because the instrument is indoors

Explanation

Measurement categories reflect the transient overvoltages expected at a location, so the instrument and its leads must both be rated for the category of the point at which they are used. Supply-side positions demand a higher category than final circuits.

Question 30Safe isolation, preparation for inspection and testing, safe working practices

When proving dead at a three-phase distribution board, which testing sequence confirms all conductors are dead?

  1. Phase to neutral on each phase, with no other combinations
  2. Phase to phase only, because the neutral is connected to earth
  3. Phase to earth on one phase only, because all phases are linked
  4. Phase to earth, phase to phase and phase to neutral on every conductor Correct answer.

Explanation

Every combination must be tested: each phase to earth, each phase to every other phase, and each phase to neutral. This confirms the state of all live conductors, since a neutral or a single phase can remain live from another source.

Question 31Safe isolation, preparation for inspection and testing, safe working practices

Before use, test leads should be:

  1. Cleaned with a damp cloth before every single test
  2. Inspected for damage and the lead continuity checked Correct answer.
  3. Stretched to check that the insulation is flexible
  4. Checked for a valid calibration certificate only, before each use

Explanation

Leads and probes are inspected for damaged insulation, cracked probes and exposed conductors, and the continuity of each lead is confirmed. A damaged lead can give false readings or expose the user to live parts.

Question 32Safe isolation, preparation for inspection and testing, safe working practices

Why should the calibration status of a test instrument be checked before use?

  1. Because calibration certificates must be displayed on site at all times
  2. To make the instrument read zero on every range
  3. So readings are accurate enough to compare with required limits Correct answer.
  4. To confirm that the instrument is still covered by its warranty

Explanation

Results are only meaningful if the instrument is accurate enough for the measurement, so calibration status is confirmed before testing. Out-of-calibration instruments can produce readings that wrongly pass or fail an installation.

Question 33Safe isolation, preparation for inspection and testing, safe working practices

After isolating and locking off a circuit, where should the voltage indicator be applied to prove the circuit dead?

  1. At the main incoming terminals, before the main switch
  2. At the point of work, on the conductors to be worked on Correct answer.
  3. On an adjacent live circuit, as a comparison
  4. On the line side of the main switch, as a cross-check

Explanation

The circuit must be proved dead at the actual point of work, because isolation elsewhere does not guarantee the conductors being touched are dead. Testing at the origin would not detect a back-feed or a borrowed supply at the point of work.

Question 34Safe isolation, preparation for inspection and testing, safe working practices

Once a circuit has been isolated and locked off, a warning notice should be:

  1. Given to the client to keep in a safe place until the work is done
  2. Fixed at the point of isolation with details of the person working Correct answer.
  3. Placed in the van until the work is completed
  4. Attached to the instrument case for reference

Explanation

The warning notice belongs at the point of isolation, where anyone attempting to re-energise will see it, and should identify who is working and why. A notice kept elsewhere serves no protective purpose.

Question 35Safe isolation, preparation for inspection and testing, safe working practices

An installation is supplied by a generator through a changeover switch as well as by the mains. What must be done before isolating a distribution board for testing?

  1. Operate the changeover switch to the generator position and begin work
  2. Isolate the mains only, because the generator is only a standby supply
  3. Identify every source of supply and isolate and lock off all of them Correct answer.
  4. Isolate the generator only, because the mains is the primary supply

Explanation

Every source of supply must be identified and each one isolated and locked off, because the board can remain live from an alternative source even when the mains is off. A single isolation point is not sufficient where dual or standby supplies exist.

Question 36Safe isolation, preparation for inspection and testing, safe working practices

When testing requires access to equipment mounted at height, what is the correct approach?

  1. Use suitable access equipment set up and used correctly Correct answer.
  2. Reach up from floor level using long test leads wherever possible
  3. Stand on the consumer unit or an adjacent pipe
  4. Stand on a wooden chair or a nearby box

Explanation

Suitable access equipment such as a step ladder or platform, set up and used correctly, is required for work at height. Improvised platforms and overreaching are common causes of falls and of accidental contact with live parts.

Question 37Safe isolation, preparation for inspection and testing, safe working practices

Why is switching off an RCD not an acceptable means of isolation?

  1. It cannot be switched off manually once it has tripped
  2. It only isolates the neutral conductor and leaves the line live
  3. It can be reset by anyone and provides no secure isolation Correct answer.
  4. It only operates on three-phase supplies

Explanation

Isolation needs a device that can be secured in the off position and provides a suitable isolating distance; an RCD can be reset by anyone and is not designed as an isolator. It is a protective device, not a means of isolation.

Question 38Safe isolation, preparation for inspection and testing, safe working practices

When using a continuity tester with long test leads, why should the lead resistance be measured and nulled before testing?

  1. To check that the circuit is live before testing begins
  2. To charge the instrument's battery before the test
  3. To increase the test current flowing through the circuit under test
  4. So lead resistance is not added to the measured circuit resistance Correct answer.

Explanation

Nulling subtracts the resistance of the leads from the reading so that only the resistance of the circuit under test is recorded. Without this, long leads can add significant resistance and give a falsely high result.

Question 39Safe isolation, preparation for inspection and testing, safe working practices

On a large industrial installation, what document is typically used to record and control the safe isolation of a circuit before work?

  1. A permit to work issued by the authorised person Correct answer.
  2. A minor electrical installation works certificate
  3. An electrical installation certificate for the premises
  4. A schedule of test results signed by the tester

Explanation

A permit to work records the isolation points, the lock-off applied and the person authorised to work, and is cancelled when the work is complete. It is a control document, not a certification of test results.

Question 40Safe isolation, preparation for inspection and testing, safe working practices

Before disconnecting a main protective bonding conductor during testing, what should be done?

  1. Disconnect it while the installation remains fully energised
  2. Isolate first and avoid leaving the installation unearthed Correct answer.
  3. Disconnect it and leave it off until the end of the working day
  4. Short it to the line conductor to confirm it is dead

Explanation

Main bonding is only disconnected where the test requires it, with the supply isolated and the conductor reconnected promptly, so the installation is never left without earthing and bonding protection for longer than necessary.

Question 41Inspection (initial verification and periodic inspection)

Which instrument is the correct choice for proving that a circuit has been safely isolated before inspection work begins?

  1. A clamp meter set to the current range
  2. A voltage indicator complying with GS38 Correct answer.
  3. An insulation resistance tester
  4. A multimeter set to the resistance range

Explanation

Safe isolation requires proving dead with an approved voltage indicator, and the indicator should be proved before and after use on a known live source. Resistance, insulation and current ranges do not provide a reliable check for the presence of dangerous voltage.

Question 42Inspection (initial verification and periodic inspection)

During a visual inspection of a domestic installation, which item should be confirmed for each final circuit?

  1. The presence of a durable circuit identification label Correct answer.
  2. The insulation resistance reading
  3. The circuit's earth fault loop impedance value
  4. The operating time of the RCD

Explanation

Visual inspection confirms matters such as identification, labelling, damage and adequacy of equipment. Measured values such as loop impedance, insulation resistance and RCD times belong to the testing part of the process.

Question 43Inspection (initial verification and periodic inspection)

When carrying out initial verification, which test is normally performed before energising the installation?

  1. RCD operating time
  2. Insulation resistance Correct answer.
  3. Earth fault loop impedance
  4. Functional testing of switches

Explanation

Dead tests are carried out before the installation is energised, and insulation resistance is one of these dead tests. Earth fault loop impedance, RCD operating times and functional checks are normally live tests performed later.

Question 44Inspection (initial verification and periodic inspection)

For a rented domestic property in England, what is the maximum interval normally required between electrical installation condition reports?

  1. 1 year
  2. 5 years Correct answer.
  3. 3 years
  4. 10 years

Explanation

The private rented sector in England requires an EICR at intervals not exceeding five years. A ten-year interval is commonly used as guidance for owner-occupied domestic premises, not for rented ones.

Question 45Inspection (initial verification and periodic inspection)

Which observation code indicates a danger that is present and requires immediate action?

  1. C1 Correct answer.
  2. C3
  3. C2
  4. FI

Explanation

C1 is used where danger is present and immediate remedial action is required. C2 indicates a potentially dangerous condition, C3 indicates improvement recommended, and FI means further investigation is needed.

Question 46Inspection (initial verification and periodic inspection)

Which certificate is used to record the addition of a new final circuit to an existing installation?

  1. Minor electrical installation works certificate
  2. Schedule of test results only
  3. Electrical installation certificate Correct answer.
  4. Electrical installation condition report

Explanation

Adding a new final circuit is not minor works, so an electrical installation certificate is required. A minor works certificate is for small alterations that do not include a new circuit.

Question 47Inspection (initial verification and periodic inspection)

Which document must be provided to the person ordering the work after initial verification of a new installation?

  1. A periodic inspection report
  2. A PAT test record
  3. A method statement
  4. An electrical installation certificate with schedules Correct answer.

Explanation

Initial verification of a new installation is recorded on an electrical installation certificate, supported by schedules of inspections and test results. A periodic report is used for condition reporting of existing installations.

Question 48Inspection (initial verification and periodic inspection)

In periodic inspection, what does sampling of the installation mean?

  1. Inspecting and testing a representative portion of the installation Correct answer.
  2. Testing only the largest circuits
  3. Testing every accessory in the installation
  4. Replacing all protective devices before testing

Explanation

Sampling means selecting a representative portion of the installation for inspection and testing, with the extent agreed and recorded. It does not mean testing every accessory or selecting circuits by size.

Question 49Inspection (initial verification and periodic inspection)

An inspector is unable to access a locked riser cupboard during a periodic inspection. How should this be handled?

  1. Test the circuits from another board and omit the limitation
  2. Ignore it because it is not part of the installation
  3. Record it as a C1 observation
  4. Record it as a limitation and agree the extent with the client Correct answer.

Explanation

Areas that cannot be accessed must be recorded as limitations, and the extent of the inspection should be agreed with the client. An inaccessible area is not automatically a dangerous condition and must not be omitted from the report.

Question 50Inspection (initial verification and periodic inspection)

A periodic inspection finds that main protective bonding to the metallic water service is missing on a TN-C-S installation. Which code is most appropriate?

  1. C2 Correct answer.
  2. C3
  3. FI
  4. C1

Explanation

Missing main protective bonding on a TN-C-S system is a potentially dangerous condition because it can affect protective conductor voltages and disconnection. It is normally coded C2 and requires urgent remedial action.