-. 1 BS 7671 includes the requirements for

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1 78 EXAM SUCCESS 'j lee WIRING REGULATIONS Paper 14 Sample test 2 The sample test below has 60 questions, the same number as the online exam, and its struture follows that ofthe online exam. The test appears first without answers, so you an use it as amok exam. It is then repeated with worked-through answers and extrats from the lee Wiring Regulations. Finally, there is an answer key for easy referene. Answer the questions by filling in the irle next to your hosen option. Setion BS 7671 inludes the requirements for ~ fixed wiring for information and ommuniation tehnology, signalling and ontrol radio interferene suppression equipment systems forthe distribution of eletriity to the publi equipment on board ships and airraft. 2 BS 7671 requires protetion against eletri shok te provided by basi and fault protetion. One method ommon toth is the use of RCDs the use of Class II equipment preventing urrent from passing through any person or livestok the use and implementation of equipotential bonding. 3 Whih one of the following types of eletrial installation is not overed by BS 7671? High protetive ondutor urrent installations Lightning protetion of buildings Conduting loations with restrited movement Highway power supplies 4 The seletion of the type of wiring and method of installation is not influened by the nature of the loation the load urrent the value of the prospetive short-iruit urrent the nature of the struture supporting the wiring.

2 2 Paper 14 EXAM PRACTICE 2 SAMPLE TEST 2 79 Setion 2 5 Band II voltage exeeds 2500 V d.. between live ondutors 2500 V d.. between ondutors and Earth 1000Va..rms 120 V d.. ripple-free A protetive ondutor onneting exposed-ondutive-parts of equipment to the main earthing terminal is known as the earthing ondutor main bonding ondutor iruit protetive ondutor bonding ondutor. 7 An area or temporary struture used for display, marketing or sales is defined as b a booth a stand an exhibition a show ~ Setion 3 "--" ~ ~ To ensure ontinuity of supply to one part of the installation in the event of failure of anoth~! part, one approah is for a separate iruit te installed for eah part to use protetive equipotential bonding Oto install larger fuses to install a 100 ma 5 type ReD ~ 9 An assessment must be made of the harmful effets of harmoni urrents of equipment on other eletrial equipment. This assessment is a hek of a external influenes ompatibility diversity maintainability.

3 3 EXAM SUCCESS Paper 14 lee WIRING REGULATIONS Every installation must be divided intiruits as neessary in order to redue the ost of installation make installation easier install a ooker failitate safe inspetion, testing and maintenane, Whih one of the following is not a potential harateristi of equipment te onsidered for harmful effets on other equipment? a Transient overvoltages d,' feedbak Prospetive short-iruit urrent Exessive protetive ondutor urrent 12 When making an assessment of the frequeny and quality of maintenane, a fator te onsidered is that power fator is monitored protetive measures for safety remain effetive starting urrents are at a minimum unbalaned loads need te heked more frequently, Setion 4 13 A BS A fuse with Uo of 230 V has a maximum tabulated Zs for 5 seonds disonnetion of.. _ Q 1,04Q 1.44Q Od 1,84Q, 14 Whih of the following is a requirement in terms of fault protetion where the protetive measure of eletrial separation is employed? a The voltage of the separated Ciruit is not more than 500 V Flexible ables and ords liable to mehanial damage are onealed Live parts are onneted t protetive ondutor Exposed-ondutive-parts are onneted to Earth

4 4 Paper 14 EXAM PRACTICE 2 SAMPLE TEST An ReO an be used as additional protetion in the event of failure of the provision for basi protetion when the Reo has a rating not exeeding 30mA 100mA 300mA 500mA. 16 Basi protetion an be provided by protetive earthing barriers automati disonnetion in ase of a fault funtional earth. 17 An obstale is not intended to prevent unintentional bodily approah to live parts prevent intentional ontat with live parts during operation be removed by use of a key ortool be seured ss to prevent unintentional removal For a non-onduting loation, the resistane of an insulating floor or wall at every point of measurement speified in Part 6 shall not be less than 45 kq where the voltage to earth does not exeed 230 V 50 kq where the voltage to earth does not exeed 500 V 55 kq where the voltage to earth does not exeed 750 V 60 kq where the voltage to ea rth does not exeed 1000 V. 19 Where eletrial separation is used to supply more than one item of urrent-using equipment. warning noties may be omitted 8 b the length of the wiring system should not exeed 500 m soket-outlets should not have a protetive ondutor ontat the provisions for basi protetion are not required.

5 82 EXAM SUCCESS 5 Paper 14 lee WIRING REGULATIONS In loations with risks of fire due to the nature of proessed or stored materials, enlosures suh as heaters and resistors shall not attain in normal onditions higher surfae temperatures than 90 C 85 C 60 C 55 C. 21 In a paper mill installation wired in PVC single-ore ables in onduit and trunking, where a fire may be aused by a resistive fault in overhead heaters with film elements, protetion against an insulation fault shall be provided by a BS 88 fuse BS EN b 300 ma RCD. 30mARCD. 22 The maximum temperature for the exposed metalli asing of a wall-mounted, ord-operated infra-red heater is 55 C 65 C 70 C 80 C. 23 Where fault urrent protetion is not required, protetion against overload urrent is generally provided by BS EN fuses an inverse-time-iag protetive devie abs 3036 semi-ehlosed fuse RCDs

6 6 Paper 14 EXAM PRACTICE 2 83 SAMPLE TEST 2 24 Regulations and do rult allow the fault urrent protetive devie te plaed on the load side of the redution in urrent-arrying apaity of a ondutor if the length of ondutor is less than 3 m the length of ondutor exeeds 3 m it is ereted in suh a manner as to redue t minimum the risk of fault urrent it is ereted in suh amanner as to redue t minimum the risk of fire or danger to persons. 25 In the formula k 2 S2 t= 12 what is the k fator for opper ondutors insulated with 70 C thermoplasti and an assumed initial temperature of 70 0? 100/86 115/ What is the required minimum impulse withstand voltage for ategory IV equipment for use in an installation with nominal voltage of 4oo/690? 2.5kV 4kV 6kV 8kV Setion 5 27 When seleting equipment for an installation, the person who makes the tinal deision over its safety would be the representative of a regional supply ompany representative of a national inspetion body designer or other person responsible inspetor and tester.

7 ~~..~----~ 84 EXAM SUCCESS 7 lee WIRING REGULATIONS Paper e 0 Ob sooe 28 Unless otherwise onfirmed as suitable, swithgear, protetive 70 e 0 devies and aessories shall not be onneted tondutors. Od 90 C. intended to operate at a temperature in exess of 29 A 70 C thermoplasti insulated and sheathed able to BS 6004 is installed in an ambient temperature of 25 C for part of the run and then enters an area at 40 C. The effet on the able will be to require lips at greater intervals redue the voltage drop inrease the bending radius derease its urrent-arrying apaity. 30 A single-phase load of 13 A is supplied via a 15 A BS 1361 fuse using single-ore 70 C thermoplasti opper ables installed to method 4 (Referene Method B). The rating fator for grouping is 0.7 and for ambient temperature 0.87, and overload protetion is te provided. The minimum aeptable size able would be 1mm mm 2 2.5mm 2 4mm ~ The minimum information ontained on a periodi inspetion and testing notie would be the date of inspetion and inspetor's name date of next inspetionaolient's name date of last inspetion and date of next inspetion ompany's address and date of next inspetion. 32 When ondutors are identified by numbers, the neutral shall be identified by the number '-~

8 8 Paper 14 EXAM PRACTICE 2 SAMPLE TEST Whih one of the following devies would not be suitable to provide overurrent protetion? Residual urrent devie to BS 4293 Cartridge fuse to BS 1362 Cartridge fuse to BS 88-6 Rewirable fuse to BS Under fault onditions, ables are subjeted to stress and thermal effets. One item not normally enountered would be eletrohemial effets eletromehanial stresses eletromagneti effets thermal damage. 35 Every onnetion between ondutors, or between ondutors and equipment, need not be seleted tount for the ondutor length material ofthe ondutor number and shape of the wires forming the ondutor ross-setional area of the ondutor Where more than one fi refighter's swith is,instalied on anyone building, eah swith must be a not more than 3.75 m from the ground in a loked loation to prevent nuisane operation eletrially linked learly marked. 37 Where safety depends upon the diretion of rotation of a motor, provision shall be made to measure the maximum and minimum speed monitor the slip frequeny prevent reverse operation prevent operation of overload devies.

9 EXAM sucteis~" ~.., lee WIRING REGULAnpNS Paper A 16 mm 2 multiore able inorporating a opper protetive ondutor is insulated with 90 C thermosetting insulation. Given a fault urrent of 500 A and a disonnetion time of 0.4 seond, the minimum aeptable size of p would be 1.Smm 2 2.5mm 2 4.0mm 2 6.0mm 2 39 When using the alternative method to Regulation of sizing a opper protetive ondutor, the minimum size te used when a opper line ondutor has a sa of 50 mm 2 would be 16mm 2 2Smm 2 3Smm 2 SOmm 2 40 The maximum urrent rating of a protetive devie proteting a iruit inluding B22 bayonet ap JamphoJders would be SA 6A 16A 20A. 41 Whih of the following is not a BS 7671 requirement when installing a heating able laid diretly in soil? It is ompletely embedded in the soil Obitdoes not suffer damage in the event of normal movement It omplies with the manufaturer's instrutions It is proteted by a 500 ma RCD Setion 6 42 During the installation inspetion proess, whih one of the following need rurt be heked? The external earth fault loop impedane Equipment in ompliane with Setion 511 Corret seletion and eretion Visible damage or defets to installed equipment

10 10 Paper 14 EXAM PRACTICE 2 SAMPLE TEST When testing 5ELV iruits, the minimum aeptable insulation resistane value is O.2SMQ O.SMQ 1 MQ 2MQ. 44 Defets identified during an initial verifiation should be noted on the ertifiate, and the lient should be informed pointed out to the main ontrator when the ertifiate has been ompleted made good before the ertifiate is issued put on asnagging list te retified later. 45 Whih of the following is not a requirement for periodi inspetion and testing? Ensuring the safety of persons and livestok from shok and burns Ensuring the property is proteted against damage from fire and heat due tn installation fault Confirmation that the installation is not damaged as to impair safety Confirmation that the supply to the installation meets all the requirements ofthe Eletriity Safety, Quality and Continuity Regulations 46 Additional work is arried out tn installation, whih omprises a soket-outlet added tn existing iruit. The paperwork te ompleted would be a Periodi Inspetion Report ashedule of Test Results aminor Eletrial Installation Works Certifiate ashedule of Inspetion$. 47 When ompleting an Eletrial Installation Certifiate, the person whoes not have to sign the ertifiate would be the tester lient onstrutor.designer.

11 EXAM SUCCESS 11 lee WIRING REGULATIONS Paper Setion 7 48 For an eletri floor heating system in a bathroom, a fine mesh metalli grid is Wlt required te onneted to the protetive ondutor of the supply iruit if the protetive measure used is b SELV eletrial separation a non-onduting loation an earth-free equipotential zone. 49 Aess to the spae under a bath is gained by unsrewing the bath panel retaining lips. This spae is lassified as a zoned zone1 outside the zones zone For SELV and PELV iruits in a bathroom, basi protetion for equipment in all zones shall be provided by obstales barriers or enlosures non-onduting loation plaing out of reah. 51 Eletrial equipment in zones 0 and 1 of a fountain shall have mehanial protetion t minimum lassifiation of AGO AG1 AG2 AG3. 52 Whih of the following would D..Qt be a requirement for an Assembly for Constrution Sites (ACS), supplying mobile urrent-. using equipment on a onstrution site? b Main equipotential bonding Overurrent protetive devies Devies for fault protetion Soket-outlets

12 12 Paper 14 EXAM PRACTICE 2 89 SAMPLE TEST 2 53 Whih one of the following is rurt inluded in the sope of Setion 70S? a a b a d Chiken-houses Stables Piggeries Staff residenes 54 In onduting loations with restrited movement, supplies to handlamps shall be proteted by a a a b a a d SELV redued low voltage supplies RCD or RCBO PELV. 55 The minimum height of overhead ondutors on aravan sites, when installed in vehile movement areas, is a a 3.0m ab 35m a 5.Bm ad 6.0m The partiular requirements for mobile or transportable units apply to a a a b generating sets mobile workshops a mobile mahinery to BS EN a d tration equipment of eletri vehiles. 57 Eletrial equipment in a irus installation must have a degree of protetion of at least a a IP33 IP4X IP44 IPXB.

13 13 EXAM SUCCESS Paper 14 lee WIRING REGULATI,ONS Setion 8 58 The ambient air temperature rating fator for 90 C thermosetting ables operating in an ambient air temperature of 60 C is Oa 0.50 Ob 0.56 O 0,63 Od 0.71, ~ A A fuse, when arrying 1800 A, has a disonnetion time of 0.2 seond 0.4 seond 4 seonds 5 seonds. 60 A 2.5 mm 2 thermoplasti insulated and sheathed flat able with protetive ondutor is laid in a eiling benbnnnnnnnnnath thermal insulatio 80 mm thik in ontat with the eiling board, as shown in the figure below. What is its installed rating? t80mm 17A 20A 21 A 27A

14 14 Paper 14 Test Paper 2 Full Q Ans Reg No Q Ans Reg No 1 A C 512, C A B A Definitions 4 B A D Definitions 35 A C Definitions 36 D B Definitions 37 C A B Table B B D C C D B 42 A 13 D Table B Table A C A D B ,5 46 C B C B A 19 B B A B D C D Table A B D 24 B A B Table D D Table B C C C D Table 4B1 29 D Table 4B1 59 A Fig 3.2A 30 D Appendix