WorksheetsOversee and Design Mock Paper A
Total questions: 70
Worksheet time: 38mins
When explaining installation details to colleagues it is important to make sure that
colleagues are tested about their understanding
technical terms are used constantly
instructions are clear and thorough
colleagues are given a copy of the installation specification
What is the internal insulating medium (material) in a M.I cable?
manganese oxide
magnesium oxate
manganese dioxide
magnesium oxide
An ECS (Electrotechnical Certification Scheme) card is valid for how many years?
10
1
5
3
Which one of the following cable system is used for underground supply cables in older installations?
SWA
XLPE (Cross-Linked Poly Ethylene)
PILC (Paper-insulated, Lead clad)
PVC/PVC
Due to bad weather conditions, your company has not been able to complete the outside work by the agreed date. This could lead to
the outside work being completed after the client has moved in
the job completion being delayed
your company requesting a variation order so that the work can be completed
cancellation of all outside works
Which one of the following cable systems provides some heat and chemical-proofing properties?
SWA
PILC
PVC/PVC
XLP
A variation order to install additional outlets will be issued by the
client
sub - contractor
site manager
contractor
Why is cable tray NOT to be used as an 'earthing conductor'?
because cable tray cannot conduct electricity
because electrical continuity cannot be guaranteed
cable tray CAN be used as an earthing conductor
because electrical insulation cannot be guaranteed
Which document details the number and types of components that are needed for a project?
gant chart
material schedule (specification)
quotation
site report
Which ONE of the following sites has to meet the specific requirements of special 'codes of practice'?
petrol stations
agriculture/horticultural installations
construction sites
caravans and caravan parks
A project is scheduled to take 160 person hours for completion. If the working day is 8 hours, what is the minimum number of staff required to complete the project within 10 days?
4
2
3
1
BS7671:2018 defines the colours of electrical conductors. What is the colour defined for a protective conductor?
yellow
brown
green and yellow
green
Identify the correct pieces of equipment that can be used to detect insulation leakage.
tong tester
phase sequence tester
continuity tester
voltage inductor
insulation resistance tester
Identify the correct pieces of equipment that can be used to measure the resistance of conductors
tong tester
insulation resistance tester
phase sequence tester
voltage inductor
continuity tester
Before starting any installation work, it is essential to first -
identify the location of the site office
identify the start and finish times
identify any potential hazards
identify the name of the 'clerk of works'
What check is made to ensure enough accessories have been delivered to site?
check delivery note against installation specification
ask the supervisor whether the delivery is correct
make a visual check with a colleague
check delivery note against items delivered
What is the preferred way of reducing excessive voltage drop in a circuit?
reduce the size of the load
increased cable CSA
increased cable length
reduced voltage
What must be kept near any combustible materials?
material guidance notes
an alarm
a fire extinguisher
a bucket of sand
Which ONE of the following systems of earthing uses the 'general mass of earth' as the earthing conductor?
TT
TN-C
TN-S
TN-C-S
Which of these is the most appropriate method for storing conduit?
In piles
On racking
Flat on the ground
Placed against a wall
BS7671:2018 wiring regulations do not 'normally' apply to which ONE of the following types of electrical equipment?
rotating machines
railway track signals
fire alarm systems
emergency lighting
British Standards were introduced to
Ensure that all work carried out anywhere in the UK is completed to the same high standard
Check that all people working in electrical installations are suitably qualified
Check that all people working on electrical installations are resident in the UK
Ensure that manufacturers only use products made in the UK
What protective device provides the function of a residual current device with a circuit breaker, in the same enclosure?
RCD
RCBO
MCB
MCCB
When installing an electrical appliance, what document should be followed?
The site drawings
The manufacturer’s instructions
The wiring diagram
The technical data
What may occur if excessive PVC cement is used when joining PVC conduit?
The joint will be weak
A barrier may form within the joint
The joint will take a long time to set
The PVC may 'degrade'
After checking a work area it may be necessary to make the area safe before starting work and also during work activities so it may be necessary to
Use barriers or tapes to section off possible hazards
Use barriers or tapes to section off possible hazards
Remember where the hazards are located
Start work immediately and deal with the hazards as they arise
Show everyone on the site where the hazards are
A document laying out the work procedure and sequence of operation is a
Site plan
Safe isolation procedure
Risk assessment
Method statement
It is important to check the condition of equipment for pre-existing damage as the contractor’s employee could be made liable for any damage whilst work is in progress. This check is best carried out by
The contractor responsible for the installation and a representative of the customer so that any pre-existing damage can be noted
Insurance representatives from both parties so that any damage can be agreed prior to any claims for compensation
The contractor responsible for the installation so that any pre-existing damage can be noted
The customer, so that there will be a record of any damage prior to the work starting
A suitable method of checking premises for any existing damage is to do a
Polarity test
Periodic inspection
Visual inspection
Insulation resistance test
Whilst carrying out electrical work some existing damage to a wall was found close to where a power socket is to be installed. What is the best action to take?
Ensure that the contractor has insurance in case the client sues the installer
Record and photograph the damage and inform the client before work begins
Ensure that the client has insurance so that a claim can be made immediately
Inform the client when the work is complete to explain the extra costs
Using table F3 of the On-Site Guide what is the de-rating factor if a group of 3 circuits are installed on a single layer on wall or floor? (abbreviation for the grouping factor is: Cg)
0.70
0.82
0.80
0.79
Before starting any installation work, steps must be taken to protect the structure and fabric of the site. This is best done by
Taking no legal responsibility if anything is damaged and completing work as normal
Trying not to damage any property whilst working but reporting any damage caused
Using a safe secure area to store all moveable fixtures and fittings and protecting all other equipment with suitable covers to keep off dirt and debris
Moving as much equipment as possible to a corner of the room so there is a clear area to work and then reinstall it after the work is finished
A flat twin cable with bare protective conductor and white outer insulation is commonly regarded as which cable type?
Thermosetting cable with low smoke and fumes properties (LSF)
Thermosetting cable without low smoke and fumes properties (LSF)
Thermoplastic cable with low smoke and fumes properties (LSF)
Thermoplastic cable without low smoke and fumes properties (LSF)
Label the parts of this cable used when supplying a three phase and neutral distribution board.
The image shown is a cable used for data transmission and;
Is known as braided flexible cable and is capable of data transmission speeds up to one gigabyte per second
Is also called coaxial cable containing four twisting pair cables within one jacket
Is often referred to as optical fibre cable since it is made from optical quality plastic
Is known as Cat 5 cable containing four twisting pair cables within one jacket
The main advantage of this containment system is that it;
Allows multiple circuits to be carried
Can be pre-wired
Is for external use only
Is cheap
If the rating of a protective device is 20A (BS3036) and the following correction factors apply to a circuit Ca (0.94), Ci (0.88), Cg (0.85) and Cf (0.725) calculate the (It) the tabulated current carrying capacity required of the cable (abbreviation for the tabulated current carrying capacity of cable is: It)
8.325A
5.89
34.52A
39.23A
Trunking bends and sets for angular work can be purchased ready-made. A craft worker still needs to know how to make bends and sets because
It is considered good practice to make bends and sets as it is the mark of a worker who takes pride
Some customers will insist that all bends and sets are created on site to reduce the cost of the installation
Despite good planning an unexpected all or ventilation pipe can appear and delays will occur of the needed part is out of stock
The job can be completed faster when bends and sets are made on site as they will always match the required profile
Power track distribution systems are commonly associated with, but not limited to, which type of circuit?
Underfloor power supplies to lighting circuits
Underfloor power supplies to socket outlets
Overhead lighting circuits (industrial and commercial)
Overhead lighting circuits (domestic)
If the tabulated current carrying capacity of a Twin & Earth cable which has been clipped direct to a wall been calculated at 40A, using table F6 of the On-Site Guide work out what size cable is required?
4mm²
5mm²
6mm²
10mm²
For outdoor lighting installations, equipment must be classified for which of these external influences? The cable factor is a 1.5mm cable is 27
Ambient temperature
Climatic conditions
Vibration
Presence of water
The maximum volt drop in a lighting circuit is?
5%
4%
3%
10%
An enclosure is labelled IP6X. What does this relate to?
Whether the enclosure is dust tight
The maximum ambient working temperature of the enclosure
How resistant the enclosure is to vibration and other mechanical stresses
The degree of protection from water that the enclosure has
Using table F5 (ii) of the On-Site Guide, determine the volt drop for a 6mm² cable which has been installed through Reference Method C (clipped direct/single phase)?
7.3 mV/A/m
6.4 mV/A/m
3.8 mV/A/m
47 mV/A/m
What is the cable type used for building management system networks?
RJ45
BCN
ADSL
Cat 5E
What type of cable is used on a fire alarm system, where operation in a fire is required for prolonged period?
MICC
SWA
Glass fibre insulated
Butyl rubber
When selecting a power tool for a particular job it should be checked to see if
It is too heavy to carry. If this is the case it should not be used for long periods of time
The tool appears damaged or makes an unusual sound when running
The cable is damaged. If this is the case it should be repaired with a suitable insulating tape before it is used
It is available in the stores and can be booked out for use
Before using laser level, precautions to be taken include
Wearing a reflective vest
Using dark glasses to the light intensity
Not looking directly at the light source as this can cause blindness
Looking directly at the light source to make sure that it is working
Using Table B6 of the On-Site Guide determine what is the maximum loop impedance value for a Type B circuit breaker which is rated at 20A
1.25Ω
1.4Ω
2.2Ω
1.75Ω
A fixing device used to hold conduit in place before plastering is known as
Gravity toggle
Butterfly clip
Rawlbolt
Crampet
When does the 80% rule regarding loop impedance values apply?
When using the On-Site Guide
When using Guidance Note 3
When using the Electricity at Work regulations 1989
When using the Wiring Regulations
A suitable fixing for conduit used outdoors is
SWA cable cleat
PVC cable cleat
Steel saddle
Galvanised saddle
If the measured earth loop impedance of a circuit is 1.1Ω, and the maximum tabulated value in the On-Site Guide is 1.75Ω what does this mean regarding shock protection.
Measured is less than 80% of the tabulated value therefore shock protection is not met
Measured value is less than 80% of the tabulated value therefore shock protection is met
Measured value is less than tabulated value therefore shock protection is met
Measured value is less than the tabulated value therefore shock protection is not met
Which of these fixings methods is suitable for holding a lightweight load on a plasterboard partition?
Screw fixing using a plastic plug
Cable clip
Rawlbolt
Spring toggle
If the prospective fault current of a 230V domestic circuit is 560A, which of the following is correct?
Zs = 2.434Ω
Ze = 2.434Ω
Zs = 0.4107Ω
Ze = 0.4107Ω
Surface mounted PVC cable should be run directly into an electrical accessory. The outer sheathing of the cable should be taken inside the accessory to a minimum of
15mm
20mm
5mm
10mm
It is essential to make good structure of a building following electrical repair work
By doing this it is certain that the customer will ask for further work to be done in the future
So that any person used the room after work is completed is not complaining about draughts through the holes in the walls
By using appropriate material before the job is signed off so that the general building structural performance and fire safety are not reduced
Because the customer expects to see everything is neat and tidy and is looking exactly like it was before the work started.
What is an overcurrent resulting from a fault of negligible impedance between conductors?
Loop impedance
Overload
Fault current
Short circuit
What is meant by assessing Thermal constraint?
A calculation to ensure that the size of the cpc is small enough to withstand a very large fault current over a short period of time.
A calculation to ensure that the size of the line conductor is small enough to withstand a very large fault current over a short period of time.
A calculation to ensure that the size of the line conductor is big enough to withstand a very large fault current over a short period of time.
A calculation to ensure that the size of the cpc is big enough to withstand a very large fault current over a short period of time.
What is a disadvantage of the fuse type pictured?
Regular maintenance is required to ensure they operate
They could possibly take twice their rating before blowing
The fuse wire requires changing on a regular basis to ensure discrimination
They can be fitted with the wrong size cartridge
Which device combines both overload and earth fault protection?
Rewireable fuse
RCD
RCBO
MCB
Where can the maximum fault current capacity of a domestic consumer unit main switch be found?
BS 7671
Written on the test sheet
On Site Guide
Written on the device
What is the maximum disconnection time for a 32Amp MCB on a 230V ac, TN supply?
0.3 seconds
4 seconds
0.4 seconds
5 seconds
Identify the correct symbol for the rating of the 'tabulated current', where correction factors have had to be applied
z
In
It
Ib
An intermediate switch used in some lighting circuits has how many terminals?
Two
Three
Six
Four
What is the minimum cross sectional area of the live conductors used for a radial power circuit, protected by a 20A circuit breaker and covering an area of 40m²?
4.0mm²
2.5mm²
1.5mm²
1.0mm²
Immersion heaters should be supplied from
Their own separate circuit
A 13Amp socket outlet
A switched spur connected from a ring final circuit
A lighting junction box
The distribution circuit to a sub main of a TN system, has an allowed maximum disconnection time of what, under fault conditions?
1s
0.2s
0.4s
5s
When hard wiring interconnected fire detectors using 3 core and earth PVC cable. What colour core is used for the interconnect lead?
Black
Yellow/green
Grey
Brown
Identify the device that operates using only the 'thermal' effect.
BS88-2
RCD
BSEN 61009
BSEN 60898
