JUNE 2018 Level 2 Technical Certificate in Electrical Installation Level 2 Electrical Installation Theory exam

Transcription

1 JUNE 2018 Level 2 Tehnil Certifite in Eletril Instlltion Level 2 Eletril Instlltion Theory exm Thursy 28 June :30 11:30 Plese note: Due to question 5 eing exlue from the originl Jun 18 pper, this question hs een reple in this oument. You shoul hve the following for this exmintion multiple-hoie nswer sheet pen with lk or lue ink non-progrmmle lultor Permitte referene mteril: BS 7671 (2015) IET On-site Guie This question pper is the property of the City n Guils of Lonon Institute n is to e returne fter the exmintion. Re the following notes efore you nswer ny questions You must use pen with lk or lue ink to omplete ll prts of the nswer sheet. Chek tht you hve the orret nswer sheet for the exmintion. Chek tht your nme n nite etils re printe orretly t the top of your nswer sheet. Inform the invigiltor if your nme or exmintion etils re not orret. Eh question shows four possile nswers (lettere,, n ); only one is orret. Deie whih one is orret n mrk your nswer on the nswer sheet with your pen. For exmple if you eie is orret, mrk your nswer like this If you wnt to hnge your nswer, nel your first hoie y filling in the nel ox elow the irle like this Then mrk the nswer whih you hve now eie is orret. For exmple if you now eie is orret, mrk your nswer like this Any other mrks on the form my invlite some of your nswers. Any lultions or rough working n e one on the question pper. Attempt ll questions. If you fin question iffiult, leve it n return to it lter. This pper ontins 60 questions. Answer them using the oxes numere 1 to 60 on the nswer sheet. The City n Guils of Lonon Institute 2018 ST J1 PO

2 1 Wht is n orgnistionl responsiility with regrs to PPE? Must e worn t ll times. Any efets must e reporte. Trining n informtion on its use must e provie. Must e use in orne with ny trining provie. 5 Whih personnel is onerne with the esign n physil integrity of uilings n other lrge strutures? Site Mnger Sfety Offier Struturl Engineer Site Supervisor 6 Wht jo role entils heking the qulity of mterils n instlltion meets the lient s requirements? Clerk of Works. Projet Mnger. Contrts Mnger. Quntity Surveyor. 7 Wht vlue is require to etermine iruit power where only the iruit resistne is known? Figure 1 2 Wht regultion oes the symol, in Figure 1, pply to? WEEE. EAWR. Control of Noise Regultions. The Pollution Prevention n Control At. 3 Wht oument sets out systemti pproh for set tsk? Permit to work. Metho sttement. Risk ssessments. Jo sheet. 4 Wht is the immeite tion tht must e tken upon isovering ollegue eing expose to n eletri shok? Pull the sulty wy. Cll for meil ssistne. Swith off the min supply. Assess the sitution. I 2 E L Z s 8 Wht vlue represents 1 MΩ? 1 x 10 6 Ω 1 x 10 3 Ω 1 x 10 3 Ω 1 x 10 6 Ω 9 Aoring to Ohms Lw, whih is the orret formul? R = V x I R = V 2 + I R = I / V R = V / I 10 Wht is the sum of ll the ngles in right ngle tringle?

3 16 Wht lultion woul e use to lulte totl resistne in series iruit? R 1 + R 2 + R 3 1 R1 + 1 R R 3 Figure 2 11 Wht is the vlue of ngle A shown in Figure 2? Wht prt of the tom is negtively hrge? Proton. Nuleus. Eletron. Neutron. 13 Wht mteril is use s n insultor? R 1 R2 R3 R 1 x R 2 x R 3 17 Wht is the length of 2.5 mm 2 opper onutor hving resistne of Ω t 20 C? The resistivity of opper is µω/m. 20 m 30 m 40 m 50 m 18 Three resistors of 12 Ω, 6 Ω n 4 Ω re onnete in prllel. Wht is the totl iruit resistne? Tungsten. Porelin. Merury. Cron. 0.5 Ω 2 Ω 22 Ω 288 Ω 14 Whih insultor is Hyrosopi? Mi. Bkelite. Polyvinyl hlorie. Mgnesium oxie. 15 How muh power is issipte y 25 Ω resistor when 4 A flows through it? 0.4 W 40 W 0.4 kw 40 kw Figure 3 19 Wht is the totl urrent for the iruit in Figure 3? 3.83 A 1.51 A 0.66 A 0.25 A 3 See next pge

4 20 Wht two vlues oes wttmeter mesure? Voltge n resistne. Cpitne n resistne. Voltge n urrent. Current n pitne. 21 Wht is the unit of mesure for mgneti flux? Weer. Henrys. Kelvin. Hertz. 22 Wht is the flux ensity when onutor of effetive length 0.25 m is moving t right ngles through mgneti fiel t veloity of 5 m/s n is generting V? 26 Wht is the unit of mesurement for inutne? Ohms. Henrys. Frs. Siemens. 27 Wht is the operting priniple of oule-woun trnsformer? Self-inution. Shre-inution. Mutul inution. Oppose inution. 28 Wht is the RMS voltge of sine wve hving pek vlue of 90 V? 1.1 T 2.1 T T T V V V V 23 Wht is the output voltge of trnsformer tht is rte t 150 kva n elivers 375 A t full lo? 56 kv 525 V 400 V 225 V 29 Wht pssive omponent is use to reue urrent in n eletroni iruit? Resistor. Thyristor. Trnsistor. Amplifier. 24 How mny primry turns will 200 kva, 3.3 kv/240 V 50 Hz single-phse trnsformer hve, when there re 80 turns on the seonry wining? 1100 turns. 833 turns. 60 turns. 3 turns. 25 Wht is Fleming s formul for lulting fore? F = B + I + L F = F = B I L B I L F = B I L Figure 4 30 Wht must e performe efore using the equipment shown in Figure 4, on site? Erth lekge test. GS 38 heks. User heks. Erth on test. 4

5 31 Wht is the minimum istne require, from the top of floor joist, for hole use to pss les through? 50 mm 60 mm 70 mm 80 mm 32 Wht is the most suitle le for fire lrm souner instlltion? Ct 5. Fire opti. Ct 6. MIMS. Figure 6 34 Wht type of onuit set is shown in Figure 6? Doule set. Bule set. 180 en. Kik. Figure 5 33 Wht is the item shown in Figure 5 use for? Drwing in. Dressing in. Filling in. Forming in. Figure 7 35 Wht type of le woul e supporte y the item shown in Figure 7? PVC SWA. MICC. SY Flex. Twin n p. 5 See next pge

6 36 Wht is the minimum height tht les must e instlle t, on tenry system ove wlkwy? 2.5 m 3 m 3.5 m 4 m 37 Wht Externl Influene within BS 7671 woul ffet the seletion of ontinment system? Cpity. Utilistion. Suitility. Afforility. 38 Wht support system woul e most suitle for running lrge SWA up uiling eletril riser? Trunking. Bsket. Ler. Conuit. 39 Wht ftor will ffet the minimum permissile s of le? Cost. Lo. Aesthetis. Prtility. 40 Wht is the nominl voltge (AC) inite y re BS EN soket? 400 V 230 V 110 V 50 V 41 Wht termintion metho is use to onnet onutor to lrge usr system? Soler. Crimp. Wele. Brze. 42 Wht is trnsmission voltge? 11 kv 25 kv 33 kv 400 kv 43 Who is responsile for the eletril meter in omesti instlltion? The owner. The eletriin. The energy supplier. The oupnt. 44 Wht evie provies Aitionl Protetion ginst eletri shok? RCD. MCB. BS 88 Fuse. BS 3036 Fuse. 45 Whih supply system uses Protetive Erth n Neutrl onutor? TT TN-S IT TN-C-S 46 Whih supply system woul hve R A vlue? TT TN-S TN-C TN-C-S 47 Whih protetive evie requires rting ftor of 0.725? BS 88-3 BS 3036 BS 1362 BS Whih of the following is Protetive Mesure ginst fults s given in BS 7671? ADS. Brriers. RCD. Insultion. 49 Whih of the following must e Erthe? Metlli servie pipe. Metlli luminire. Steel ir uting. Struturl steel. 6

7 50 Wht is the purpose of Bsi Protetion? To protet les. To protet equipment. To prevent eletri shok. To prevent mge to instlltion. 51 Why re Erthing onutors instlle? To onnet together expose n extrneous onutive prts. To provie link etween ll extrneous onutive prts. To hieve si protetion. To hieve fult protetion. 52 Wht essile prts woul require Protetive Boning Conutor onnetion? Steel struturl ems. Metlli onuit system. Steel trunking system. Metlli le try. Questions 56 to 60 refer to the following senrio. A new single-phse eletril instlltion within n offie is to e wire using PVC/PVC insulte n shethe flt profile 70 C thermoplsti le. Dt les re to e instlle y suontrtor using the sme ontinment systems, n the Z e vlue for this instlltion is 0.35 Ω. The les re to e instlle using mixture of surfe, PVC onuit, metlli le try n PVC two-omprtment o trunking. The sheule for the finl iruits is shown in the tle elow. The instlltion supply is to e supporte vi solr photovolti system to e instlle on the flt roof of the uiling whih is 6 m from groun level. Live Type of CPC Protetive Ciruit Conutor No Designtion mm 2 mm 2 Devie Length Mteril 1 Rilpower BS EN m Copper 2 Rilpower BS EN m Copper 53 A iruit supplying 13 A lo is wire using le hving stte voltge rop of 11 mv/a/m n length of 32 m. Wht woul e the voltge rop for this iruit? 0.45 V 3.52 V 4.58 V 9.15 V 54 Wht oes Prt M of the Builing Regultions give guine on? 3 Ring finl iruit 4 Ringfinl iruit 5 2 kw Spe heter 6 2 kw Wter heter 7 6x100W luminires 8 6 x 100 W luminires BS EN m Copper BS EN m Copper BS EN m Copper BS EN m Copper BS EN m Copper BS EN m Copper Tle 1 Heights of soket-outlets. Fire omprtments in uilings. Energy effiieny of lighting iruits. Depths of les hses in wlls. 55 Wht type of rwing is ommonly use to show the positioning of eletril equipment? Ciruit. Lyout. Wiring. Shemti. 56 Why is omprtmentl trunking utilise within this instlltion? To keep ifferent oloure les prt. To seprte Bn I n Bn II iruits. To seprte les to reue ey urrents. To keep lighting n power iruits prt. 57 When ler is only nhore t groun level, wht is the require minimum length to enle the inspetion of the solr photovolti pnels? 6.2 m 7.2 m 8.2 m 9.2 m 7 See next pge

8 58 Whih prt of the RCBO opertes uner overlo onitions? 60 Why oes BS 7671 reommen neutrls to e instlle t light swithes? Resiul urrent trip. Eletro-mgneti trip. Chemil trip. Therml trip. 59 Wht is the Z 5 vlue for iruit 5, shown in Tle 1, uner operting onitions? To filitte eletroni swithing evies. To ensure short iruits re voie. To enle lights to e fully isolte. To provie emergeny lighting test filities Q 0.68 Q 0.74 Q 0.82 Q NOW GO BACK AND CHECK YOUR WORK IMPORTANT- Are the etils t the top of the nswer sheet orret? Hve you fille in your nswers in INK in the pproprite oxes on the nswer sheet? 8