1 Exam Prep Air Conditioning A, B and Mechanical Practice Exam 5 · 2018. 3. 29. · 1 Exam Prep Air Conditioning "A", "B" and Mechanical Practice Exam 5 **QUESTIONS 1 THROUGH 5 ARE

1 Exam Prep

Air Conditioning "A", "B" and Mechanical Practice Exam 5

**QUESTIONS 1 THROUGH 5 ARE FOR MECHANICAL CONTRACTORS ONLY**

1 A device to shut off the fuel supply to a main burner is a/an?

A Air Shutter B Barometric Regulator C Flame safeguard D Air Arrester

2 Floor furnaces shall have how many inches clearance above grade on the control side?

A10 B 18 C 24 D 48

3 Longitudinal pullout resistance must be at least equal to for plastic pipe.

A 5,000 PSI B Breaking strength C Tensile strength D 5,000 PSIG

4 The vent height is 6 feet. The vent and connector diameter is 6 inches. Ventilation is FAN-MIN. The maximum input rating of a Type B Double-Wall vent with double wall connectors serving 3 category 1 appliances using a 1-foot rise is how many BTUPH?

A 72,000 B 58,000 C 164,000 D 104,000

5 The maximum gas demand for an outlet is 30 cubic feet per hour and the length of pipe from the point of delivery to the most remote outlet is 60 feet. The size galvanized pipe in inches required using a designated pressure drop of 0.50 inch water column with a 0.60 specific gravity and a heating value of 1000 Btu per cubic foot using natural gas is?

A 1 B 3/4 C 1/2 D 1/4

1

6 Devices us:xi to activate motor starters or contactors are?

A Battery operated B Computer activated C Electromagnetically-operated D Motion activated

7 Piping to be embedded in concrete must be prior to pouring concrete.

A Inspected B Pressure tested C Cleaned D Greased

8 A vessel in which refrigerant is vaporized to produce a refrigerating effect is a(n)?

A Absorber B Concentrator C Condenser D Evaporator

9 Condensate drains from rooftop units may discharge onto rooftops?

A Never B Only as a last resort, if no other means of discharge is possible C If the condensate does not discharge into a street, alley or other area so as to cause a nuisance D Only if the condensate will evaporate completely within 12 to 24 hours

10 Women prefer an effective temperature degree(s) higher than men.

A4 B 3 C2 D 1

11 A layer of clings to the face of any object.

A Heat B Air C Moisture D Dirt

12 Shorted compressor motor windings?

A Are indicated by a greater than normal resistance B Will immediately blow fuses or trip the circuit breaker C Always cause the motor to shut down D Can draw excessive amperage

13 In a compressor, the resistance indicated is between the start and run terminals_

A Positive B Negative C Most D Least

14 The of an air-vapor mixture is the heat which affects only the dry bulb temperature of the mixture.

A Specific heat B Sensible heat C Latent heat D Dry heat

15 It is not recommended that one refrigerant be exchanged for another in a system?

A If the refrigerant has already been changed out previously B Unless capacity or efficiency of the compressor can be enhanced by doing so C Without approval of the compressor or system manufacturer D At all

16 A sufficient amount of frost, or ice, will not be removed from the coil to allow proper refrigeration to occur, if the defrost termination point is?

A Too low B Too high C Ignored D Set incorrectly

17 A vessel in which vaporized refrigerant is liquefied by removal of heat is called a(n)?

A Absorber B Concentrator C Condenser D Evaporator

18 The following absorbents can be used in commercial absorption machines except?

A Calcium chloride B Ethylene glycol C Lithium bromide D Lithium chloride

3

19 When cooling water by evaporation. the 3anal number of degrees the water temperature is reduced is known as the cooling?

A Average B Coefficient C Range D Ratio 20 Potential relays operate?

A On the electromagnetic principle B Using electrical resistance C Using the "Domino Principle" D Using a self-regulating conductive ceramic

21 The percentage of warm water entrained by the air and carried away from the cooling device is called the?

A Drift B Effluent C Flux D Waste

22 The theoretical horsepower required to drive a fan can be determined by multiplying the quantity of air (in cfm's) by the? A Fan total pressure (at the fan outlet), divided by 6356, multiplied by the brake horsepower B Fan static pressure (at the fan outlet), divided by 6356, multiplied by the brake horsepower C Fan static pressure (at the fan outlet), divided by 6356 D Fan total pressure (at the fan outlet), divided by 6356

23 Using the velocity method to design ductwork, the velocity is?

A Evenly assigned to each section of the ductwork B Loosely estimated for each section of the ductwork C Highest at the end of the duct D Highest at the fan outlet

24 To determine the heat loss from a pipe, expressed in btuh's per lineal foot?

A Apply the formula 3.14 xRxR B Refer to Table 3-19 C Use special tools to make the calculations D Only the pipe size must be known

25 The primary purpose of a motor starter or contactor is to?

A Make the compressor start up more quickly B Increase the overall efficiency of the compressor C Provide switching action of high current and voltage required by a compressor D Protect the compressor

4

26 The voltage rating of any capacitor must be the one being replaced.

A No more than two percent higher or lower than B No more than five percent higher or lower than C Equal to D Equal to or greater than

27 Potential relays are relays.

A Backup B Current C Sequencing D Starting

28 A six ton or smaller nominal capacity unit may discharge condensate?

A Only to a sanitary sewer drain, storm sewer drain or French drain B Onto rooftops, so long as the unit is equipped with an auxiliary drain pan C To a gutter, roof drain or other approved location D Anywhere, so long as it does not create a public nuisance

29 A Start Kit is designed for use when conditions are encountered that prevent the PSC motor from starting normally.

A Compressor B Hard C Jump D PSC

30 An overcharge of refrigerant will cause?

A A low discharge pressure B A high discharge pressure C The system to seize D The condenser tubes to freeze

31 A device used to transfer heat between two physically separate fluids is a heat?

A Absorber B Exchanger C Mixer D Sensor

32 Which is extremely dangerous to refrigeration systems?

A Too much refrigerant B Too little refrigerant C Moisture D Lack of maintenance

5

33 Type 3003-0 aluminum tubing with high-pressure fittings may not be used aiita'7

A Most refrigerants B Fluorinated hydrocarbons C Methyl-chloride D Air

34 A refrigerant leak?

A Can be ignored without serious consequences B Should be found and repaired C Is usually difficult and laborious to repair D Requires tools to pinpoint

35 The power element of a thermostatic expansion valve contains a(n) charge.

A Electromagnetic B Slight C Thermal D Vapor

36 No may be installed on fuel oil return piping.

A Fittings B Valves C Gauges D Lines

37 The result of moisture freezing in the refrigerant flow control orifice is poor refrigeration, accompanied by a?

A Lower than normal suction pressure B Copper color on the steel valves and parts C Higher than normal suction and discharge pressure D Discoloration of the oil

38 Auxiliary drain pans on cooling units must have a than the unit or coil dimensions in width and length.

A Minimum depth of 1 1/2 inches and cannot be less than 3 inches larger B Minimum depth of 1 3/4 inches and cannot be less than 3 1/2 inches larger C Minimum depth of 1 1/2 inches and cannot be more than 4 inches larger D Minimum depth of 2 inches and cannot be more than 3 1/2 inches larger

39 The defrost termination point is the?

A Temperature at which the defrost period ends B Point at which the defrost period ends C Point when all the frost has melted D Point when the system returns to normal operation

6

40 To check for shorted moor windings, first?

A Perform a visual inspection of the wire insulation B Use the ohmmeter to check the continuity from one terminal to another C Remove all external wiring from the motor terminals D Consult the motor manufacturer's data to determine the correct resistance requirements

41 Of prime importance to reliable torch brazing is?

A Taking enough time to do a good job - not rushing B Being knowledgeable about the properties of various metals C The general cleanliness of all surfaces D Using high quality tools

42 Exhaust outlets serving Type 1 hoods must? A Terminate not less than 40 inches above the roof opening B Have a lining thickness of at least 4 inches laid on a 1/2 inch bed . C Be at least 8 feet away from any combustible construction D Have a wall thickness of at least 0.518 inches

43 To braze steel to copper, use? A Phos-copper brazing alloys B Silver brazing alloys C Steel brazing alloys D Filler metal

44 Pressure-relief devices, fusible plugs and purge systems located within the machinery room must terminate outside the structure at a location at least feet from any window, ventilation opening or exit.

Al2 B 15 C18 D 20

45 Applying "finger" pressure to check for correct belt tension should result in approximately inch(es) total deflection.

A2 B 1 1/2 C1 D 1/2

46 Do not use hand-held instruments to take high voltage measurements higher than?

A 599 B 600 C 700 D 750

7

47 Attics containing appliances requiring access must be provided with an opening and an unobstructed passageway?

A At least 30 inches high, 24 inches wide and not more than 22 feet in length measured along the centerline of the passageway from the opening to the appliance B At least 33 inches high, 22 inches wide and not more than 20 feet in length measured along the centerline of the passageway from the opening to the appliance C Large enough to allow an "average" adult access D Large enough to allow removal of the largest appliance

48 Ordinarily, exhaust outlets cannot be located less than feet horizontally from parts of the same or contiguous buildings, adjacent property lines and air intake openings into any building.

A8 B 9 C10 D 1 1

49 A single-wall metal chimney serving appliances which operate at temperatures between 1500 and 1800 degrees Fahrenheit should terminate feet above the roof opening.

A3 B 10 C18 D 20

50 Liquid adhesive coatings used on filters must have a flashpoint not lower than degrees Fahrenheit.

A 325 B 335 C 345 D 355

51 Pressure-relief devices, fusible plugs and purge systems located within the machinery room must terminate outside the structure at a location at least feet above the adjoining grade level.

A10 B 12 C15 D 18

52 A certificate of test must be provided for all systems containing pounds or more of refrigerant.

A 50 B 55 C 70 D 75

8

53 Plastic pipe or tubing used: to pipe beating panels must be rased?

A 100 psi at 180 degrees Fahrenheit B 110 psi at 180 degrees Fahrenheit C 100 psi at 190 degrees Fahrenheit D 110 psi at 190 degrees Fahrenheit

54 Return piping must connect to the of the fuel oil tank.

A Outside B Inside C Top D Bottom

55 Hard start capacitor kits should be wired in?

A Series B Parallel C Dual phase D Split phase

56 The 8-inch common face brick exterior is ten feet tall by 22 feet long. The inside of the wall is finished with 5/8 inch sand plaster. Inside design conditions will be 78 dry bulb and 65 wet bulb when the outdoor temperature is 97 dry bulb and 80 wet bulb. The heal, gain from the wall should be? Wind speed averages at 15 miles per hour.

A Less than 500 Btuh B Between 500 and 1,000 Btuh C Between 1,000 and 1,500 Btuh D More than 1,500 Btuh

57 Which is not a type of main burner?

A lnshot B Inset C Slotted port D Ribbon

58 The Type 1 medium duty island hood is 3 feet by 8. feet. The minimum airflow required when deep-fat frying is? inch round duct with a velocity of 35,000 CFM's is?

A 4,000 CFM's B 2,500 CFM's C 3,000 CFM's D 3,500 CFM's

9

59 According to the Trane Manual, the friction loss in inches of water per hundred feet of 36 inch round duct with a velocity of 35,000 cfm's is?

A .2 B .5 C .7 D .9

60 A should always be provided on the suction side of the compressor.

A Particulate basket B Filter C Liquid strainer D Scale trap

61 Hydronic piping systems must be tested times the maximum system design pressure, but not less than 100 psi.

A Hydrometrically at one and three-quarters B Hydrometrically at one and one-half C Hydrostatically at one and three-quarters D Hydrostatically at one and one-half

62 When the at the suction of the compressor becomes clogged, the suction pressure may fall.

A Particulate basket B Filter C Liquid strainer D Scale trap

63 According to the PIPEFITTERS HANDBOOK, a flange curved to fit a boiler or tank and attached to a threaded pipe is which flange?

A Saddle B Weld-neck C Slip-on D Outlet

64 Which pipe is made by welding along a scarfed longitudinal seam in which one part is lapped by the other?

A Spiral weld B Resistance weld C Lap weld D Longitudinal seam

10

65 A pipe weld where one pipe is expanded on the end to allow the entrance of the end of the other pipe is which weld?

A Slip B Butt C Flange D Cup

66 According to PIPEFITTERS HANDBOOK, a tee made in which the branch is larger than the run is a/an?

A Bull head B Straight C Reducing D Lateral

67 A fitting, either cast or wrought, having one side outlet at any angle other than 90 degrees is a/an?

A Branch tee B Rolling offset C Manifold D Wye

68 According to PIPEFITTERS HANDBOOK, a tee made with easy (long radius) curves between body and branch is which tee?

A Long radius B Standard C Double sweep D Straight

69 According to PIPEFITTERS HANDBOOK, a valve with a short section of a cone through which a hole is cut so that fluid can flow through when the hole lines up with the inlet and outlet, but when rotated 90 degrees, flow is blocked is a/an?

A Ball B Plug C Gate D Globe

70 According to PIPEFITTERS HANDBOOK, a joint for connecting a pipe under pressure to a rotating machine is a/an joint?

A Rotary pressure B Ball C Swivel DU

11

-1 Brazing is?

A Soldering B Soft soldering C Joining metals using brass D Fine soldering

72 According to PIPEFITTERS HANDBOOK, the maximum support spacing for a 2 inch schedule 80 PVC pipe should be?

A 4.5 B 5.1 C 5.8 D 7.7

73 According to PIPEFITTERS HANDBOOK, the weight of 30 feet long 3" steel pipe, schedule 40 when full of water is how many pounds?

A 96 B227 C 300 D 323

74 According to PIPEFITTERS HANDBOOK, the actual inside diameter of a Type K copper tube with a nominal diameter of 1" is?

A 0.652 B 0.995 C 1.125 D 7.583

75 According to PIPEFITTERS HANDBOOK, the type of heat necessary for hard soldering or brazing is?

A White B Yellow C Red D Blue

12

76

BACKDRAFT DAMPER

FAN

NOTE: = RIOT TUBE

FIGURE 1 - GARAGE EXHAUST SYSTEM Refer to Figure I. The following traverse readings were taken with a pitot tube:

Station Velocity Pressure

At Point (3a) 1 .24

2 .25

3 .36

At Point (3b) 1 .62

2 .64

3 .66

At Point (3c) 1 .32

2 .33

3 .34

The air volume handled by the fan in this system is? Assume standard air density.

A Less than 2,000 cfm B Between 2,000 and 2,400 cfm C Between 2,400 and 2,800 cfm D More than 2,800

77

The following data was obtained from a test report on the fan shown in Figure 1.

At Point (1) Static Pressure Velocity Pressure

At Point (2) Static Pressure Velocity Pressure

The fan static pressure is?

A +0.25 inch wg B +0.50 inch wg C +1.75 inches wg D +2.00 inches wg

= -2.0 inches WG =+0.50 inch WG

= +0.25 inch WG = +0.25 inch WG

0 78

0 COIL SECTION

OUTSIDE AIR

SIDE VIEW FIGURE 2

CENTRAL STATION AIR CONDITIONING UNIT

The central station air conditioning unit shown in Figure 2 was installed in accordance with the following specifications:

Cooling coil entering conditions: 78?F DB, 65?F WB Cooling coil leaving conditions: 56?F DB, 54?F WB Supply air fan: 9,200 cfm at 1-1/2 inches WG static pressure; 3 HP motor, 460 volts, 3 phase, 60

Hertz

The size of the refrigeration system required for this unit is?

A Less than 28 tons B Between 28 and 30 tons C Between 30 and 32 tons D More than 32

15

SEA LEVEL 70 DEG. F. DB

FIGURE 3 DRYING OVEN

79

STATIC PRESSURE TAPS

1120 DEGREES F. DB

The fan shown in Figure 3 is classified as a/an?

A Forward curved centrifugal fan B Backward inclined blade centrifugal fan C Air foil centrifugal fan D Axial fan

16

AIR HEATER

FAN

PLAN VIEW DUCT FROM OUTSIDE

SUPPLY DUCT

36"

SIDE MEW

FIGURE 4, FIELD ERECTED HEATING SYSTEM 2 1

80

The air heater shown in Figure 4 heats air at standard air conditions up to 200F. The density of the hot supply air is? Refer to Trane.

A Less than 0.055 pounds per cubic foot B Between 0.055 and 0.065 pounds per cubic foot C Between 0.065 and 0.075 pounds per cubic foot D More than 0.075

17

CONVERTER

••

...••••■■■■••••■■•■

■

GATE - air VALVE

41100111

CHECK VALVE

140 DEG. F. FROM HOT WATER HEATING SYSTEM

HOT WATER PUMP

81

180 DEG. F. HOT WATER HEATING SYSTEM

STEAM CONTROL VALVE

SATURATED STEAM- 15 PSG

GATE VALVE CONDENSATE

FIGURE 5 - HOT WATER CONVERTER_

The hot water flow rate required for the system shown in Figure 5 is? Assume 1,000,000Btu per hour.

A Less than 35 gpm B Between 35 and 45 gpm C Between 45 and 55 gpm D More than 55

18

ANSWER KEY - EXAM 5

1 C Florida Building Code, Fuel Gas, 2010 Page 2.5

2 B Florida Building Code, Fuel Gas, 2010 609.4

3 C Florida Building Code, Fuel Gas, 2010 403.11

4 B Florida Building Code, Fuel Gas, 2010 Table 504.3(1)

5 C Florida Building Code, Fuel Gas, 2010 Table 402.4(2)

6 C Air Conditioning/Refrigeration Troubleshooting Handbook 20

7 B Florida Building Code, Mechanical, 2010 1209.2

8 D Trane Air Conditioning Manual 205

9 C Florida Building Code, Mechanical, 2010 307.2.1


11 B Trane Air Conditioning Manual 37

12 D Air Conditioning/Refrigeration Troubleshooting Handbook 5



15 C Trane Air Conditioning Manual 123

16 A Air Conditioning/Refrigeration Troubleshooting Handbook 73


18 A Trane Air Conditioning Manual 238



21 A Trane Air Conditioning Manual 248







28 D Florida Building Code, Mechanical, 2010 307.2.1

29 B Air Conditioning/Refrigeration Troubleshooting Handbook 39




33 C Florida Building Code, Mechanical, 2010 1107.5.5





38 A Florida Building Code, Mechanical, 2010 307.2.3




42 A Florida Building Code, Mechanical, 2010 506.3.12.1


44 D Florida Building Code, Mechanical, 2010 1105.7




48 C Florida Building Code, Mechanical, 2010 506.3.12.3

49 B Florida Building Code, Mechanical, 2010 Table 511.2

50 A Florida Building Code, Mechanical, 2010 605.1

51 C Florida Building Code, Mechanical, 2010 1105.7


53 A Florida Building Code, Mechanical, 2010 1209.1

54 C Florida Building Code, Mechanical, 2010 1305.4


56 D Trane Air Conditioning Manual

22X 10 X.39 X 19=1,630.2

24/Table 3-5


58 A Florida Building Code, Mechanical, 2010 507.13.3

500 X 8 = 4,000

59 C Trane Manual 282



62 C Pipefitter's Handbook 5-90

65 D Pipefitter's Handbook 5-89

66 A Pipefitter's Handbook 5-87



69 B Pipefitter's Handbook 5-91

70 A Pipefitter's Handbook 5-92



73 D Pipefitter's Handbook 5-11/17

5-11: 3.201 5-17: 7.58

3.201 + 7.58 X 30 = 323.43

74 B Pipefitter's Handbook 5-13


21

76 D

Station Velocity Pressure At Point (3a) 1 .24

2 .25 3 .36

.85 + 3 = .28333

V = 4005 X Square root of .28333 V = 4005 X .5322 V = 2,132 CFM = Area X Velocity 10" Diameter = 5" Radius CFM = (3.1416 X 5" X 5" + 144) X 2,132 CFM = 1,163

At Point (3b) 1 .62 2 .64 3 .66

1.92 + 3 = .64

V = 4005 X Square root of .64 V = 4005 X .8 V = 3,204 CFM = Area X Volume 8" Diameter = 4" Radius CFM = (3.1416 X 4" X 4" + 144) X 3,204 CFM = 1,118

At Point (3c) 1 .32 2 .33 3 .34

.99 +3 =.33

V = 4005 X Square root of .33 V = 4005 X .5744 V = 2,300 CFM = Area X Volume 8" Diameter = 4" Radius

CFM = (3.1416 X 4" X 4"+144) X 2,300 CFM = 803

Total Air Volume = 3a CFM + 3b CFM + 3c CFM Total Air Volume = 1,163 + 1,118 + 803 Total Air Volume = 3,084

77 C

Formula: Fan Static = Static Pressure at Fan Outlet - Static Pressure at Fan Inlet

Point (1) is the input, Total = -2.0 + .50 = -1.5 Point (2) is the output, Static is = +.25

Fan Static = + .25 -(-1.5) Fan Static = 1.75

78 A

Use enthalpy chart BTUH = CFM X 4.5 X Enthaiphy Difference BTUH = 9200 X 4.5 X (30 - 22.6) BTUH = 9200 X 4.5 X 7.4 306,360 + 12,000 = 25.53

79 D

80 D

81 C

BTUH = GPM X 500 X Temp Difference 1,000,000 = GPM X500 X40 GPM = BTUH + (500 X Temp Difference) GPM = 1,000,000 + (500 X 40) GPM 50

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1 Exam Prep Air Conditioning A, B and Mechanical Practice Exam 5 · 2018. 3. 29. · 1 Exam Prep Air Conditioning "A", "B" and Mechanical Practice Exam 5 **QUESTIONS 1 THROUGH 5 ARE

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