"B" Contractors Practice exam First the legal stuff: This practice test will not ensure that you will pass the
government test. There are no guarantees nor implications that anything on this
page is correct. These are probably not the same questions you will get on a government
exam. This page is for entertainment purposes only. ---------------------------------------------------------------------------------------------------------------------------------------------------- Hi Everyone: Are you ready to write for your contractors license. You will also need a current code course. You need to have a subscription to the bc bulletins, a copy of the Safety Standards (quite a few questions regarding regulations) and Standard for overhead line construction (a couple of pole questions). You will get 3 1/2 hours when you write the exam. Have fun !! ?? The BCSA has recently informed me that they have removed the docked marks for incorrect answers. Thanks Ivan..... 1. What size neutral supported cable (Triplex) would you use to feed a shed with an 85 amp demand at 120/240 volts? a) #3 AWG NS1 b) #4 AWG NS1 c) #6 AWG NS1 Answer_________ Rule(s)___________ 2. Can you run conductors other than service conductors in the same conduit used for service conductors if you stay within the allowable conduit fill Answer__________Rule_____________ 3. Ground rods must be a minimum of ________long and _____apart Answer__________Rule_____________ 4. Fuses used to protect a Clothes dryer may be type "D" time delay? Answer__________Rule_____________ 5. What is the living space in a 2 story single house 10m x 14m outside measurements with a basement? Walls are 200 mm thick. Answer_________ Rule(s)___________ 6. What is the minimum Length for a "ufer" Ground? Answer__________Rule_____________ 7. Is it permissable to install incoming and outgoing neutrals to the screws on a duplex receptacle or must they be pigtailed? Answer__________Rule_____________ 8. Is there ever permissible have 347/600 volt space heating in an apartment building ? Answer__________Rule_____________ 9. In a class 1 Zone 1 location, Rigid conduit must have at least ______Tapered Threads engaged Answer__________Rule_____________ 10. Can you use an open type (ODP) 3 phase motor in a class 1 Zone 2 hazardous location? Answer__________Rule_____________ 11. NMS cable may be used for fire alarm wiring in a combustable building? Answer__________Rule_____________ 12. For #________and larger electrical equipment must have a smooth hub or an insulating bushing? 13. What is meant by a "Trip Free" Breaker. a) The Handle will not prevent the breaker from tripping b) The Breaker will not trip under Overcurrent c) The Breaker will not trip under short circuit conditions d) The Breaker automatically resets after a fault Answer_________ Rule(s)___________ 14. What rule states that all breakers must be "trip free" Answer: ________________ 15. For service conductors to be considered outside you would look at rule #________________ Rule_____________ 16. What is the Maximum Rating of overcurrent devices permitted for a nms branch circuit supplying only 2 lamp 120 volt florescent ballasts in a residence. Answer_________ Rule(s)___________ 17. What color is generally used for an insulated ground wire? a) Neutral gray b) Green c) Black 18. What is the Maximum Voltage to ground for a Residence Lighting Circuit? Answer:_____________ Rule(s)_______________ 19. What would the maximum rating be in the above question if this were in a commercial Building? Answer_________ Rule(s)___________ 20. what is the minimum # breaker spaces for a single family residence with a 150 amp service with a central gas furnace. Answer__________Rule_____________ 21. What is the minimum size nipple used between a 400 amp 3 phase splitter feeding a 100 amp 3 phase 4 wire disconnect with R90xlpe conductors Answer__________Rule_____________ 22. What size and what type of fuse is required for a 3kw hot water tank at 240 volts in a residence? Answer_________ Rule(s)___________ 23. . You have 6 #4 wires in a conduit. The conductors are RW90 xlpe copper & ambient is 60 deg c. What is your allowable current in each conductor a) 45 amps b) 68 amps c) 56.95 amps 24. May Swimming pools have a receptacle within 3 meters if it is on a ground fault breaker? Answer_________ Rule(s)___________ 25. What must you do when running cables through a fire rated wall? Answer_________ Rule(s)___________ 26. Does table 2 apply to 3 phase 4 conductor cable when determining conductor ampacity? Answer__________Rule_____________ 27. Which of the following is acceptable when installing a 575/240/120 volt lighting transformer: a) Ground the transformer to the existing 575 volt system ground electrodes b) Ground the first switch to the existing 575 volt system ground electrodes c) Ground the transformer to new electrodes and bond to the existing 575 volt __system ground electrodes. d) Any of the Above Answer__________Rule_____________ 28. Do You Require a separate disconnect in a remote control system if you disconnect the remote system with the main power disconnect? Answer_________ Rule(s)___________ 29. The bending radius of armoured cable shall be at least _____times the diameter of the cable 30. In a spray booth is the ventalation ducting considered a hazardous location? Answer__________Rule_____________ 31. What is the maximum height for overhead service conductors above ground? a) 1.5 meters b) 15 meters c) 9 meters 32. Nonmetalic sheathed cable shall have not less than ______of air space when in proximity of a heating duct Answer__________Rule_____________ 33. What demand factor is used on a swimming pool heater? a) 100% b) 40% c) 25% 34. Calculate the following: 600 volt 300 KVA 3 phase transformer 2.5% (z) Impedence, 3 phase 4 wire 120/240 volt secondary 1) Total secondary impedence 2) Primary fuse size 3) Secondary Conductor size Rw90 copper 4) Secondary Grounding conductor size 5) Primary conductor size Rw90 Copper 35. Can a #1 copper neutral wire be identified at the ends only? 36. The maximum distance triplex can span is______? Answer__________Rule_____________ 37. On 24 volt Class 2 low energy circuits, the current must be limited to ____ Amps? a) 4.167 amps b) less than 10 amps c) 31 amps 38. How much would a 57 meter run of 2" emt expand when the expected temperature range is -30c to +40c ? Do you need an expansion joint? Answer__________Rule_____________ 39. Find the current of a 3 phase 575 volt 300 kw load at 90% power factor. 40. Does a plug under the soffits on a house need to be a GFCI? a) Yes it is outside! b) No, It is protected by the roof, therefore always dry. c) Only if its lower than 2.5 Meters 41. Can a typical 120/240 volt single family dwelling have a 240 volt heating thermostat? Answer__________Rule_____________ 42. What type of enclosure is needed for outdoor use that could be subjected to direct streams of water? Answer__________Rule_____________ 43. Must equipment have access for Maintenance after it has been installed?. Answer_________ Rule(s)___________ 44. A conduit contains 4 #12 conductors and is run up the hoistway from the bottom limit switch in an elevator shaft. Must the wires inside the conduit be supported if the conduit is run 40 meters high? Answer__________Rule_____________ 45. The point where overhead service conductors attach shall be a minimum of _____ and a maximum of _______below the service cap. Answer__________Rule_____________ 46. What is the minimum size conductor run aerially between builduings with a span of 25 meters Answer__________Rule_____________ 47. What is the power factor of a water treatment plant at 600 volts, 3 phase drawing 500 amps when a wattmeter reads 450kw ? Answer__________ 48. Can a run of teck cable used underground to street lights be spliced and buried? Answer__________Rule_____________ 49. What is the maximum distance you can run a 2 conductor #10 nms cable feeding 2 x 6 volt remote 25 watt emergency lamps? Answer__________Rule_____________ 50. Is it necessary that BX cable be fastened when run above suspended ceilings? Answer__________Rule_____________ 51. What is the voltage rating of nms cables? a) 150 volts or less b) 300 volts c) 600 volts 52. How many spare breaker spaces must be left unused in a single family house? Answer__________Rule_____________ 53. Must a separate ground conductor be installed in emt used in a concrete slab? Answer__________Rule_____________ 54. Are duplex plug receptacles are required in an elevator pit? Answer__________Rule_____________ 55. is it generally permissable to use aluminum boxes in reinforced concrete slabs? Answer__________Rule_____________ 56. What size conduit is required for the following 600 volt wires: 2 x #4 R90 XLPE 2 x #10 R90 XLPE 2 x #14 R90 XLPE 1 x #10 Bare Ground Answer__________Rule_____________ 57. Do 575/120 volt motor control transformers located in motor starters and MCC's need to be grounded? Answer__________Rule_____________ 58. What is the maximum allowable voltage drop in a feeder or branch circuit? Answer__________Rule_____________ 59. Can a System Grounding conductor be Aluminum? Answer__________Rule_____________ 60. If the ampacity of a neutral for a 3 phase high pressure sodium lighting system only carrying the unbalanced load is capable of being one wire size smaller, can the neutral size be reduced? Answer__________Rule_____________ 61. Considering the following, find the total resistance: A cable with a total resistance of 5 ohms feeds 4 parallel circuits. Each of the parallel circuits have cables with 4 ohms. What is the total resistance of everything? Answer__________ 62.Calculate for the following 3,000 sq meter sawmill: The conductor size, overcurrent and overload size for the following 575 volt, motors. service factor is 1.15: Main Service feeder size: Main fuse size: 1-100 hp (full voltage starter) 1-125 hp (Reduced voltage starter) 1-30 hp (Full voltage starter) 1-25 hp (Full voltage starter) 2- 7.5 hp (Full voltage starters) 1-50 hp syncronous op at 75% pf Also has a 3 phase 575 volt lighting panel with 30kw lighting Also has 4 x 5kw space heaters Also has a 30 kva 575/120/208 tranny with a 20 kw misc load on it. 63. Panels can't be in Clothes closets according to rule #____________ Rule_____________ 64. Can 120 volt Control voltage for 575 volt a motor be supplied from a breaker in a lighting panel? Answer__________Rule_____________ 65. What is the minimum clearance that nms cable may be run without running boards or other protection when run in an attic space on the top of ceiling trusses? Answer__________Rule_____________ 66. A wire has a diameter of 3/16". What is the diameter in mils? a) 187.5 mils b) 1472 mils c) 2387 mils 67. Calculate for the following apartment with a 120/208 volt 3p 4 wire service: 12 suites-all with electric heat Suite type 1: Suite type 2: Suite type 3: 80 sq meters 90 sq meters 100 sq meters 12 kw range 14 kw range 14 kw range 3 kw hot water 3 kw hot water 3 kw hot water 4 kw dryer 4 kw dryer 4 kw dryer 4 kw electric heat 5 kw electric heat 6 kw electric heat House load contains: 15 kw 208 volt single phase electric heat with thermostats in hallways 6 kw incandescent 120 volt lighting 3 x 6kw electric dryers 208 volt single phase 1 x 4.5 kw washing machine 208 single phase 8.5 kw metal halide perimeter lighting 4 x 5kw hot water heaters single phase 208 volt 20 unrestricted car plugs 1 20amp 3 phase elevator motor Find service size and suite feeders. Answer__________ 68. What table gives the size for the bare grounding conductor for a 200 amp ungrounded delta 480 volt system? Answer__________ 69. What is the minimum depth for 240 volt 3 conductor #12 teck cable run underground below a home driveway if the cable had a treated 2x6 over them? Answer__________Rule_____________ 70. If you mount an open dry type transformer on a wooden wall covered with Cement board, there must be an air space of _______ Answer__________Rule_____________ 71. What is the maximum current a class"C" Accredited Rep can work with? a) 200 amps b) 400 amps c) 600 amps 72. Must smoke detectors be on a separate circuit on a residence? Answer__________Rule_____________ 73. What is the minimum overhead clearance for service conductors over a home driveway? Answer__________Rule_____________ 74. Ground fault protection in a solidly grounded system over 150 and less than 750 volts shall have protection if over ___________Amps? Answer__________Rule_____________ 75. How deep does a ground rod have to be buried if encountering rock bottom? a) 600 mm b) 3 meters c) 1.5 meters 76. What Maximum Leakage Current Must a GFCI Breaker trip at? a) 2 ma b) 4 ma c) 5 ma 77. Do you have to count the bare ground wire in conduit fill calculations? 78. The setting depth of a pole shall be at least _____% of the pole length. Note: There are Power pole questions on the exam. You must have the "Standard for overhead line construction", and i suggest you read through it before taking the test. 79. The area around an outside gas pump at a service station within ______ meters of the gas pump and up to _____mm above the ground shall be a class 1 zone 2 area. 80. Explosive gas atmospheres which are not likely to exist in normal operations, and if they do |
Answers to "B" Contractors Practice exam 1. "B " #4 AWG ns1 Table 36 2. No Rule 6-036 3. 3 meters long and 3 meters apart 10-702 4. yes rule 14-610 & 14200 5. Top floor = 10 mtrs minus .4 mtrs (for both walls) x 14 mtrs minus .4 mtes (for both walls)= 130.56 mtr sq Ground floor = 10 mtrs minus .4 mtrs (for both walls) x 14 mtrs minus .4 mtes (for both walls)= 130.56 mtr sq Basement = 10 mtrs minus .4 mtrs (for both walls) x 14 mtrs minus .4 mtes (for both walls) x 75% = 97.92 mtr sq Total = 359.04 mtr sq 6. 6 meters Rule 10-702 (2)(a) 7. No they must be pigtailed Rule 4-034 (4) 8. Yes if you comply with rule 2-106 9. 5 Rule 18-106 (3)(a) 10. Yes Rule 18-168 (2) 11. Yes 32-102 (2)(a) 12. #8 12-610 13. "A"The handle will not prevent it from tripping. 14. Rule 14-300 (1). 15. 6-208 16. 15 amps Rule 30-104 (a) 17. b) Green 18. Rule 2-106 and Rule 30-102 19. 20 amps Rule 30-104 (c) 20. 30 circuits 8-108(1) 21. 1 1/4" Table 6 22. Size 15 Amp Type "d" hrc form 1 fuse Rule 14-610 23. "A " 45.96 amps 24. Yes but no closer than 1.5 meters Rule 68-064 (2) 25. Prevent Fire Spread 2-126 26. yes Rule 4-004 (3) 27. "D" Rule 10-206 and 10-504 28. no 14-608 29. 6 12-614 (1) 30. Yes Rule 20-402 (1) (a) 31. "C" 9 meters 32. 25 mm Rule 12-506 (4)(a ) 33. "A" 100% cec rule 8-222(1) (a)( v) 34 a Answer: 300kva x 100 = 30000000 = 33310 amps 2.5 x 208 x 1.732 900.64 34b Answer: Primary current: 300 kva = 289 amps Then 26-258 600 x 1.732 125% x 289 = 361 amps Since they dont make a 361 amp fuse, the next larger size is 400 amps. 34c Answer: Secondary current: 300 kva = 833 amps Then 26-256 (3) 208 x 1.732 125% x 833 = 1042 amps Table 2 and 8-106 (1) 800 kcm parallel runs. 34d Answer: table 17 3/0 ground 34e Answer: 500 kcm for 361 amps. 35. Yes Rule 4-030 36. 38 meters Rule 12-318(c) 37. "A" 4.167 amps 38. 12-1118 & appendix b steel coefficient = 0.0114 per degree per meter Temperature difference = 70 deg c 57 x 70 x .0114 = 45.48 mm Yes you need an expansion Joint over 45 mm 39. 334.7 amps Watts divided by (volts x 1.732 x power factor) = 300000/575 x 1.732 x .9 =334a 40. "C" Not over 2.5 meters 41. Yes- Max is 150 volts to ground (Not leg to leg) Rule 2-106 42. Type 4 rule 2-400 43. yes-2-118 44. Yes every 30 meters. Rule 12-120 and table 21 45. 150mm, 300mm Rule 6-116 46. #8 copper or # 4 Aluminum Rule 12-308 (b) 47. Kw divided by KVA =.87 or 87% 48. Yes Rule 12-12-112 (4)(b) 49. Rule 46-306 (1) Wattage is 2 x 25=50 watts Find lamp resistance at dropped reduced voltage 50 / 5.7 volts=7.917 ohms Max voltage drop = 5% of 6 volts = .3 volts R=E/I so .3 volts divided by 7.917 amps = .037895 ohms that the wire can have. #10 copper is .00102 ohms per foot .00118 Divide max wire resistance by ohms per foot .037895 / .00118 = 37.16 feet Divide 37.16 feet by 2 for there and back wire 37.17 / 2 = 18.6 ft. dist from source 50. Yes Rule 12-618 & 12-510 51. "B " 300 volts Table D1 52. 2 empty spaces rule 8-108(2) 53. Yes 10-804(c)(iii) 54. Yes 1 needed Rile 38-025 55. No Rule 12-1310 (3) 56. Table 10 2 x #4 = 52.46 x 2 = 104.92 Total 169.71mm sq 2 x #10 = 15.67 x 2 = 31.34 Table 8 says 40% max conduit fill 2 x #14 = 8.89 x 2 = 17.78 Table 9 says 1" conduit 1 x #10 = 15.67 = 15.67 57. Yes 10-116 58. 3% 8-102 (1)(c) 59. No Rule 10-802No-- not on electric discharge lights Rule 4-022 (2)(a) 60. No-- not on electric discharge lights Rule 4-022 (2)(a) 61. 1/rt = 1/r1+1/r2+1/r3+1/r4; 1/rt = 1/4+1/4+1/4+1/4; rt=4/4 = 1 ohms all the parallel circuits would be in series with the 5 ohm cable, so the total resistance would be 6 ohms. 62. Table 44 28-106 Table 2 1-125 hp (Reduced voltage starter) 156.25 amps 125 amps #1 R90 The above being largest motor taken at 125 amps x 125% 1-100 hp (full voltage starter) 99 amps 125 amps #1 R90 1-30 hp (Full voltage starter) 32 amps 40 amps #8 R90 1-25 hp (Full voltage starter) 27 amps 33.75 amps #8 R90 2- 7.5 hp (Full voltage starters) 9 amps 11 amps #14 R90 1-50 hp syncronous op at 90% pf 44 x 1.1= 48.4amps 55 amps #6 R90 Total load of motors = 380.65 amps Motor Feeder is 28-108 (1)(a) and Table 2 at 380.65 amps is 500 kcm R90 wire to feed the MCC for the motors Overload protection is 28-306 125 hp=156.4 amps; 100 hp is 125 amps; 30 hp is 40 amps; 7.5 hp is 11.3 amps Overcurrent protection is:28-200 (a) and Table 29 175% for time delay fuses so: 125 hp is 218 amps max----200 amp fuse 100 hp is 174 amps max----150 amp fuse 30 hp is 56 amps max------50 amp fuse 7.5 hp is 15.8 amps----------15 amp fuse 50 hp is 84.7 amps----------80 amp fuse The rest of the sawmill loads: lighting...............................................30,000 watts Heat....................................................20,000 watts x 75% Rule 8-210(b)=15000 watts Misc....................................................20,000 watts Watts per meter load....8-210 & Table 14 ......................3,000 x 25= 75000 145000 / (575*1.732) = 146 amps Total load = 380.86 + 146 amps = 520 amps for main service conductor Therefore Table 2 --- Parallel 250 kcm cables or single 800 kcm Ground from table 18 for ungrounded systems is #1 copper 63. Rule 26-402 64. No. Rule 3034 (1) (b) 65. 1 meter Rule12-514(a) 66. "A" 1 mill = .001" 3 divided by 16 x 1000 = 187.5 mils 67. Suite Loads Suite type 1 Suite type 2 Suite type 3 First 45 mtr sq 3500 w 3500 w 3500 w Next 45 mtr sq 1500 w 1500 w 1500 w Next 90 mtr sq ------ ------- 1000 w Heat: First 10 kw @ 100% 4000 w 5000 w 6000 w Range: First 12 kw at 6000w 6000 w 6000 w 6000 w over 12 kw @ 40% 800 w 800 w Other loads over 1500 w are taken at 25%: Dryer 4 kw@25% 1000 w 1000 w 1000 w Water Htr @ 25% 750 w 750 w 750 w Totals 16,750 w 18,550 w 20,550 w For suite feeder size: Watts / Voltage 81 Amps 89 Amps 99 Amps Next, Remove the Heat from the suites for now: 12750 w 13550 w 14550 w Largest Suite at 100% 14550 x 100% = 14550 w Next 2 largest at 65% 2 x 14550 x 65%= 18915 w Next 2 at 40% 14550 + 13550 x 40%= 11240 w Next 7 at 25% 3x13550 + 4x12750 x 25%= 22913 w Total 67618 watts Now Do the Heat from the suites: 4 suites @ 4000 watts = 16,000 watts 4 suites @ 5000 watts = 20,000 watts 4 suites @ 6000 watts = 24,000 watts Total 60,000 watts 1st 10,000 watts @ 100% = 10,000 The rest @ 75% = 50,000 x 75% = 37,500 Total 47,500 watts House Load: Electric Heat @ 75% 15000 x 75% = 11,250 watts Incandescent lighting @ 75% = 6000 x 75% = 4500 watts Dryers @ 75% = 3 x 6000 = 18000 x 75% = 13500 watts Washing Machines @ 75% = 4500 x 75% = 3375 watts Perimeter lighting @ 75% = 6375 watts Hot water heaters @ 75% = 4 x 5000 x 75% = 15000 watts Car plugs: 20 x 1200 watts x 75% = 18000 watts Elevator Motor @ 75% = 20 a x 208 v x 1.732 x 75% = 5398 watts Total 77398 Watts Total Apartment load: Suites 67618 watts Heat 47500 watts House 77398 watts Total 192,516 watts Find Amps: 192,516 divided by (208 x 1.732), so total load is 535 Amps 68. Table 18 69.450 mm minus 150 mm for mechanical protection Rule 12-012 (1) (2) (3) Tab 53 70. 6mm Rule 26-248 (3) 71. "A" 200 amps 72. No Rule 32-110(a) 73. 4 Meters Rule 6-112 (2)(b) 74. 1000 amps Rule 14-102 (1) (a) 75. "A" 600 mm 76. "C " 5 millamps 77. Yes Rule 12-1014 78. 10 % Rule 106-12 Note: There are Power pole questions on the exam. You must have the "Standard for overhead line construction", and i suggest you read through it before taking the test. 79. 6 meters, 450 mm Rule 20-004 (6) 80. Class 1 zone 2 Rule 18-006 (c)(1) |
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Practice Exam |
