17th exam questions. enjoy

[simpson93]

Introduction: The Structure of BS7671:2008.

1. Which of the following is correct? The Regulations are split into seven:

1. Parts
2. Chapters
3. Sections
4. Regulations

2. In the Regulation 536.1, the ‘536’ relates to which of the following?

1. Part
2. Chapter
3. Section
4. Regulation

3. Regulation 512.1.1 relates to which of the following?

1. Compliance with standards.
2. Fire propagating structures.
3. Suitability of equipment in relation to the nominal voltage.
4. Main protective bonding conductors.

4. The Regulations relating to Insulation Resistance testing can be found in which of the following Regulation groups.

1. 537-1
2. 442.1
3. 612.3
4. 331.1

5. Part 4 of BS7671:2008 relates to which of the following?

1. Inspection and Testing.
2. Protection for safety
3. Definitions
4. Assessment of general characteristics.

6. Information relating to Selection and Erection of equipment can be found in which of the following.

1. Part 1.
2. Part 3.
3. Part 5.
4. Part 7.

Introduction: The Structure of BS7671:2008.

Things to find out. (If time permits.)



In Regulation 414.3.2 what is the related chapter number?




What does the Regulation in Q1 above relate to?




In Regulation 527.2.1 what is the Regulation group number and what is its title?































Part 1:
Scope, Objective, and Fundamental Principles of BS7671:2008.

1. Which of the following Regulations are non-statutory?

1. BS7671 Requirements for Electrical Installations (IEE Regulations).
2. Electricity Safety, Quality and Continuity Regulations 2002.
3. Electricity at Work Regulations 1989.
4. Health and Safety at Work etc Act 1974.

2. Which of the following is excluded from the scope of BS7671?

1. Equipment of aircraft.
2. Caravans.
3. Commercial premises.
4. Agricultural and horticultural premises.

3. Which of the following is included in the scope of BS7671?

1. Lightening protection systems.
2. Equipment of motor vehicles.
3. Those aspects of mines and quarries covered by statutory Regulations.
4. Photovoltaic systems.

4. Which of the following is not a preferred frequency outlined in BS7671?

1. 40Hz.
2. 50Hz.
3. 60Hz
4. 400Hz.

Things to find out. (If time permits.)

What are the maximum a.c. and d.c. voltages as specified in Chapter 11?


Does BS7671 apply to the design, erection and verification of an electrical installation in a fairground?


Does BS7671 apply to the design, erection and verification of electrical equipment in an aircraft?


Name two statutory documents that have a relationship with BS7671.


Name three types of premises that may need special consideration due to them being covered by licensing.



Part 2:
Definitions of BS7671:2008.


1. The description ‘A part providing a defined degree of protection against contact with live parts from any usual direction of access’ is the definition for which of the following?

1. Barrier.
2. Accessory.
3. Insulation.
4. Enclosure.

2. Which of the following is not a general category of external influences?

1. Construction of the building site.
2. Ambient temperature.
3. Utilization.
4. Environment.

3. The definition ‘Conductive part of equipment which can be touched and which
is not normally live, but which can become live when basic insulation fails’ describes which of the following?

1. Extraneous conductive part.
2. Exposed conductive part.
3. Live part.
4. Protective conductor.

4. The definition ‘A conductive part liable to introduce a potential, generally earth potential, and not forming part of the electrical installation’ describes which of the following?

1. Extraneous conductive part.
2. Exposed conductive part.
3. Live part.
4. Protective conductor.

5. A residual current device offers protection against which of the following?

1. Earth fault current.
2. Overlaod.
3. Short circuit current.
4. Live to neutral faults.

Things to find out. (If time permits.)


List the systems or services which will typically require main protective bonding.


What is the correct defined term for the part of a fuse designed to melt when the fuse operates.

What is the difference between overload and overcurrent?


What is the difference between class 1 and class 2equipment?

What earthing system does PME relate to?

What is the difference between extra low voltage and low voltage?

Review the earthing systems TNCS, TNS, and TT and consider how these systems are installed practically.

 

[simpson93]

Part 3:
Assessment of general characteristics of BS7671:2008.


1. Which of the following items of information might you be required to supply to the distributor prior to receiving a connection?

1. Maximum Demand
2. Nominal Voltage
3. Type and rating of the over current device at the origin
4. External earth fault loop impedance

2. Which one of the following is not a reason given in BS7671 for dividing circuits?

1. To avoid hazards and minimize inconvenience
2. Prevent the indirect energizing of a circuit intended to be isolated
3. Facilitate safe inspection, testing and maintenance
4. To make it easier for the owner to carry out functional switching

3. Which one of the following is not a characteristic to be considered under the heading compatibility?

1. D.C. feedback
2. Continuity of conductors
3. Starting currents
4. Transient over voltages

4. Which one of the following is not recognised as a source for safety services?

1. Separate feeder
2. Storage batteries
3. Distributors supply without a backup
4. Generator sets independent of the normal supply

Things to find out. (If time permits.)

Make a list of the characteristics to be considered for continuity of service.


Give an example of where starting currents may occur?


Outline the requirements for the connection of line conductors, related neutrals and
circuit protective conductors into a distribution board.


Describe the problems associated with the dangerous practice of borrowing neutrals.


Part 4:
Protection for safety BS7671:2008.


1. Which of the following provides basic protection?
A) Protective bonding
B) RCDs
C) FELV
D) Insulation of live parts

2. Which of the following is not a protective measure?
A) Placing out of reach
B) SELV
C) Electrical separation
D) Automatic disconnection of supply

3. Which of the following is not a basic protection provision?
A) Placing out of reach
B) Insulation of live parts
C) Protective bonding
D) Barriers or enclosures

4. Which of the following may provide additional protection?
A) Placing out of reach
B) Insulation of live parts
C) Non-conducting location
D) RCDs

5 A barrier or enclosure requires a degree of protection to at least:
A) IP2X
B) IPX2
C) IP4X
D) IP44

6 For basic protection provision a readily accessible top surface requires a degree pf protection to at least:
A) IP2X
B) IPX2
C) IP4X
D) IP44
7 Which of the following provides basic protection?
A) Protective bonding
B) RCDs
C) FELV
D) Insulation of live parts




8. The maximum disconnection time for a TT system where shock protection is provided by an RCD with a nominal voltage of 230v a.c. is which of the following?
A) 0.2s
B) 0.4s
C) 1s
D) 5s

9. The maximum disconnection time for a TN system with a nominal voltage of 400v a.c. is which of the following?
A) 0.2s
B) 0.4s
C) 1s
D) 5s

10. The maximum earth fault loop impedance for 0.4s disconnection time with U[SUB]0[/SUB] of 230 V for a BS 1361 20A fuse is which of the following:
A) 1.15 Ω
B) 1.7 Ω
C) 1.77 Ω
D) 2.80 Ω

11. The maximum earth fault loop impedance for 0.4s or 5s disconnection time with U[SUB]0[/SUB] of 230v for a BS 60898 type C 32A circuit breaker is which of the following:
A) 0.36 Ω
B) 0.57 Ω
C) 0.72 Ω
D) 1.44 Ω

12. The maximum earth fault loop impedance for 5s disconnection time with U[SUB]0[/SUB] of 230 V for a BS 88A fuse is which of the following:
A) 0.19 Ω
B) 0.25 Ω
C) 0.33 Ω
D) 0.70 Ω

13. The maximum earth fault loop impedance to ensure RCD operation in accordance with Regulation 411.5.3 for non-delayed RCD to BS EN 61008 with rated residual operating current of 100mA with U[SUB]0[/SUB] of 230V is which of the following:
A) 100 Ω
B) 460 Ω
C) 500 Ω
D) 1667 Ω




14. The maximum voltage of a separated circuit:
A) 60V a.c.
B) 120V a.c.
C) 230V a.c.
D) 500V a.c.

15. Apart from where an installation is controlled or under the supervision of skilled or instructed persons, how many items of current-using equipment can be supplied from an unearth source with simple separation is which of the following?
A) 1
B) 2
C) 4
D) An unlimited number

16. The maximum nominal voltage for a SELV or PELV system is which of the following?
A) 25V a.c. and 60V ripple-free d.c.
B) 50V a.c. and 60V ripple-free d.c.
C) 50V a.c. and 120V ripple-free d.c.
D) 120V a.c. and 60V ripple-free d.c.

17. Insulation and/or barriers or enclosures must be provided for SELV or PELV circuits if the equipment is immersed or if the nominal voltage exceeds which of the following?
A) 25V a.c. and 60V ripple-free d.c.
B) 50V a.c. and 60V ripple-free d.c.
C) 50V a.c. and 120V ripple-free d.c.
D) 120V a.c. and 60V ripple-free d.c.

18. Which of the following cannot be used as a source for SELV or PELV system?
A) Autotransformer
B) Safety isolating transformer
C) An electrochemical source
D) Specific electronic devices

19. To Provide additional protection an RCD must have which of the following characteristics?
A) Rated residual current 30mA and operate in 200ms when tested with 150mA.
B) Rated residual current 300mA and operate in 40ms when tested with 150mA.
C) Rated residual current 30mA and operate in 200ms when tested with 30mA.
D) Rated residual current 30mA and operate in 40ms when tested with 150mA.

20. The operating time for an RCD providing additional protection when tested at a residual current of I[SUB]∆n[/SUB] is which of the following?
A) 30ms
B) 40ms
C) 150ms
D) 300ms

21. An a.c. circuit is protected by a 20A Type C circuit breaker and supplementary bonding may be a requirement. In relation to the accessible exposed-conductive-parts of this circuit and extraneous-conductive-parts, what would be the maximum resistance that would determine the requirement for supplementary equipotential bonding?
A) 0.25 Ω
B) 0.5 Ω
C) 1.0 Ω
D) 2.0 Ω

22. An a.c. circuit is protected by a 45A BS 1361 fuse and supplementary bonding may be a requirement. In relation to the accessible exposed-conductive-parts of this circuit and extraneous-conductive-parts, what would be the maximum resistance that would determine the requirement for supplementary equipotential bonding?
A) 0.21 Ω
B) 0.96 Ω
C) 1.04 Ω
D) 4.8 Ω

 

[simpson93]

Part 5:
Selection and erection of equipment BS7671:2008.

1. Which of the following would not be classed as voltage band I?
A) A domestic bell circuit
B) A domestic lighting circuit
C) Data cabling
D) Signalling circuitry

2. Voltage band II relates to which of the following?
A) SELV
B) PELV
C) ELV
D) LV

3. Where circuits of Voltage Bands I and II are to be run together in a trunking which of the following is not permitted?
A) All cables are insulated to Band I
B) All cables are insulated to Band II
C) All cables are insulated as for low voltage circuit
D) The cables are installed in a separate compartment within the trunking

4. Where an underground power cable crosses or is in close proximity to an underground telecommunications cable, which of the following is the required minimum clearance?
A) 50mm
B) 100mm
C) 150mm
D) 450mm

5. Which of the following must not be used as an earth electrode?
A) An earth rod
B) A gas service pipe
C) Underground structural metalwork
D) Earth plates

6. Which of the following is the minimum cross-sectional area where a protective conductor is run separately (not an integral part of a cable or formed by a conduit) and does not have mechanical protection?
A) 1.5mm[SUP]2[/SUP]
B) 2.5mm[SUP]2[/SUP]
C) 4.0mm[SUP]2[/SUP]
D) 6.0mm[SUP]2[/SUP]





7. In the formula S=ÖI[SUP]2[/SUP]t
K , A factor taking account of the resistivity, temperature coefficient and heat capacity of the conductor material is symbolised by which of the following?
A) S
B) I
C) t
D) K

8. What is the K factor of a 90[SUP]0[/SUP]C thermosetting (rubber) copper cable where the protective conductor is incorporated in a cable or bunched with cables
A) 85
B) 94
C) 143
D) 176

9. Where a final circuit is intended to supply one or more items of equipment, such that the total protective conductor current is likely to exceed 10mA and the protective conductor is mechanically protected, the minimum csa for a single copper conductor should be which of the following?
A) 2.5mm[SUP]2[/SUP]
B) 4.0mm[SUP]2[/SUP]
C) 6.0mm[SUP]2[/SUP]
D) 10mm[SUP]2[/SUP]

10 The minimum size for a supplementary bonding conductor connecting two extraneous-conductive-parts where mechanical protection is provided should be which of the following?
A) 2.5mm[SUP]2[/SUP]
B) 4.0mm[SUP]2[/SUP]
C) 6.0mm[SUP]2[/SUP]
D) 10mm[SUP]2[/SUP]

















Part 6:
Inspection and testing BS7671:2008.

1. Model Forms for certification and reporting are to be found in which of the following locations in BS7671?
A) Part 4
B) Part 6
C) Appendix 4
D) Appendix 6

2. Which of the following types of electrical installation work would not be suitable for the issue of a Minor Electrical Installations Works Certificate?
A) A socket-outlet added to an existing ring final circuit
B) A socket-outlet added to an existing radial circuit
C) A replacement socket-outlet
D) A new lighting circuit

3. The minimum value of insulation for SELV and PELV circuits should be which of the following?
A) Not more than 0.5MΩ
B) Not less than 0.5MΩ
C) Not more than 1.0MΩ
D) Not less than 1.0MΩ

4. For initial testing, which of the following is part of the correct sequence?
A) Continuity, polarity, Ring continuity, insulation
B) Polarity, continuity, ring continuity, insulation
C) Insulation, continuity, polarity, ring continuity
D) Continuity, ring continuity, insulation, polarity

5. For a new installation which of the following persons completes the section on the Electrical Installation Certificate that recommends the time period until the next inspection and test?
A) The designer
B) The installer
C) The inspector
D) The owner












Part 7:
Special installations or locations BS7671:2008.


1. The interior of a bath tub or shower basin would be described as which of the following?
A) Zone 0
B) Zone 1
C) Zone 2
D) Outside the zones

2. For installed electrical equipment in Zone 0, the degree of protection must be at least which of the following?
A) IPX0
B) IPX4
C) IPX5
D) IPX7

3. Which of the following is correct? Socket-outlets other than SELV socket-outlets
A) May be installed in Zone 1
B) May be installed in zone 2
C) May be installed in locations 3m beyond the zone 1 boundary
D) May not be installed in a location containing a bath or shower

4. A shaver unit to BS EN 61558-2-5 for use in a location containing a bath or shower uses which of the following protective measures?
A) Automatic disconnection of supply
B) electrical separation
C) Non-conducting location
D) earth-free local equipotential bonding

5. Which of the following protective measures/provisions is allowed in a location containing a bath or a shower?
A) non-conducting location
B) Placing out of reach
C) automatic disconnection of supply
D) earth-free local equipotential bonding

6. Which of the following voltages for use with a SELV switch may be used in zone 1?
A) 12V a.c. rms
B) 30V a.c. rms
C) 60V ripple-free d.c.
D) 120V ripple-free d.c.



7. the electrical appliance inlet to a caravan must have a minimum degree of protection to which of the following?
A) IPX2
B) IPX4
C) IP34
D) IP44

8. The electrical inlet to a caravan should be not more than which of the following?
A) 0.4m above ground level
B) 0.5m above ground level
C) 0.8m above ground level
D) 1.8m above ground level

9. A flexible cord supplying a caravan with a rated supply current of 16A requires a minimum cross-sectional area of which of the following?
A) 1.5mm[SUP]2[/SUP]
B) 2.5mm[SUP]2[/SUP]
C) 4.0mm[SUP]2[/SUP]
D) 6.0mm[SUP]2[/SUP]

10. A flexible cord supplying a caravan with a rated supply current of 32A requires a minimum cross-sectional area of which of the following?
A) 2.5mm[SUP]2[/SUP]
B) 4.0mm[SUP]2[/SUP]
C) 6.0mm[SUP]2[/SUP]
D) 16.0mm[SUP]2[/SUP]

11. the recommended length of a flexible cord unit (within plus or minus 2m) used to supply a caravan is:
A) 10m
B) 15m
C) 25m
D) 50m

12. Where cables are installed in a caravan and unless they are enclosed in rigid conduit they should be supported:
A) 0.25m for vertical and horizontal runs
B) 0.4m for vertical and horizontal runs
C) 0.25m for vertical runs and 0.4m for horizontal runs
D) 0.25m for horizontal runs and 0.4m for vertical runs

 

[simpson93]

just noticed there are afew wrong ill fix em up when i got abit more time+ post answers