ICE Practice

ICE Practice

Multiple ChoiceIdentify the letter of the choice that best completes the statement or answers the question.

1. The resistance to air flow of ducts, coils, filters and other surfaces is called:a. velocity c. static pressureb. total pressure d. stratification

ANSWER: CPOINTS: 0 / 1FEEDBACK:

2. Using an ohmmeter, you measure zero (0) ohms between "C" and "S" terminals. This most likely means:a. start winding is open c. internal overload is openb. start winding is shorted d. start winding is good

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3. A "start kit" for a compressor:a. decreases start winding

resistancec. increases starting torque

b. increases start winding resistance

d. decreases starting torque


4. Which of the following would most likely cause head pressure to rise (cooling mode)?a. clogged filter c. non-condensables in the systemb. a frosted evaporator d. plugged filter/drier


5. How much heat (approximately) is produced by a 5 KW heater?a. 5000 c. 10000b. 7500 d. 17000

ANSWER: DPOINTS: 0 / 1FEEDBACK:

6. The point at which a heatpump produces exactly 100% of the structure heat loss is called the:a. thermal balance point c. heating seasonal performance

factorb. coefficient of performance d. equalization temperature

ANSWER: APOINTS: 0 / 1FEEDBACK:

7. What instrument is used to measure static pressure?a. inclined manometer c. mercury manometerb. velometer d. anemometer


8. The purpose of the internal bleed port on some types of TXV is to:a. maintain full flow to the

evaporatorc. equalize pressures in the "on"

cycleb. compensate for evaporator

pressure dropd. equalize pressures in the "off"

cycle


9. Why must you generally energize the crankcase heat for at least 24 hours prior to starting a compressor that has been off for a long time?a. reduce the oil viscosity c. warm the compressor for easier

startingb. reduce the amount of refrigerant

trapped in the oild. increase the oil viscosity


10. One advantage of multi-tapped, direct drive PSC motors is:a. it is in constant operation c. the amp draw remains constant

b. CFM changes are easily made d. it moves more air than a belt drive


11. A device that removes the start capacitor from the circuit when a hermetic compressor reaches about 80% operating sped is the:a. impedance relay c. run capacitorb. centrifugal switch d. potential relay


12. Which of the following can cause a frosted evaporator?a. bad compressor valves c. an undersized duct systemb. high suction pressure d. an overcharged evaporator


13. When checking a compressor motor with an ohmmeter, the highest reading would be from:a. start to common c. start to runb. main to run d. common to run


14. The most likely reason for a compressor to cycle on and off while the condenser fan runs continuously is:a. low refrigerant charge c. open run windingb. low thermostat setting d. excessive load


15. A blower motor is cycling on and off with the thermostat fan switch set to "on". The most likely cause is:a. start capacitor c. transformerb. motor overload d. wall thermostat


16. Which of the following could cause the limit switch to open the circuit?a. fan control is open c. gas valve stuck shutb. transformer is burned out d. cracked heat exchanger


17. What is the most accurate method of charging a heatpump in the heating mode?a. put the unit in cooling and

charge by superheatc. charge to proper sub-cooling

b. weigh in an exact charge d. charge by superheat in heating mode


18. A continual roll-out on a gas furnace could be caused bya. a plugged heat exchanger c. excessive air flowb. excess combustion air d. low air flow


19. What causes the liquid line defrost sensor on a heatpump to initiate a defrost?a. a discharge temperature at the

compressor over 150Fc. increase in liquid line

temperatureb. decrease in liquid line

temperatured. constant, stable liquid line

temperature


20. Where should vibration eliminators be installed in a duct system?a. only on the supply c. after the first transitionb. only on the return d. between the air handler and the

first piece of duct


21. The fan limit control sensesa. temperature rise across the

furnacec. supply air temperature

b. return air temperature d. flue temperature


22. When should suction line filter/driers be installed?a. when non-condensables are in

the systemc. installing a new system

b. replacing a compressor following a burnout

d. suction line pressure drop is below 5 PSIG


23. The component used to reduce liquid entering a compressor is called a:a. receiver c. filter/drierb. accumulator d. muffler


24. Most residences do not have mechanical fresh air intakes. Why?a. infiltration is used to meet fresh

air needsc. most homes have fresh air

controlsb. air cleaners are used to supply

fresh aird. local codes prevent it


25. Lifting flames in a natural draft gas furnace is most likely caused by:a. low manifold pressure c. to much secondary airb. excessive gas pressure d. inadequate primary air


26. Nominal manifold gas pressure on a natural gas, atmospheric draft furnace is:a. 3"-4" wc c. 3psig - 4 psigb. 10"-12" wc d. 10psig to 12psig


27. The primary reason for sequencers on electric heat units is:a. increase inrush current c. ensure all elements are

energized at the same timeb. lower inrush current d. prevent all elements from being

energized at the same time


28. An increase in latent load on the evaporator will most likely cause:a. no change in evaporator

pressure but an increase in condenser pressure

c. a increase in evaporator and condenser pressure

b. a decrease in evaporator and condenser pressure

d. an increase in evaporator pressure and no change in condenser pressure


29. Nominal indoor airflow through a standard efficiency heatpump evaporator is:a. 200 CFM per ton c. 400 CFM per tonb. 300 CFM per ton d. 500 CFM per ton


30. An oil gun burner ignites the atomized oil by

a. an ignition module c. ceramic hot surfaceb. a primary control d. electric arc between electrodes


31. How would you best check to see if a fixed resistance crankcase heater is working with power supplied ?a. a megohmmeter c. a volt meterb. an ammeter d. an ohmmeter


32. Which instrument(s) would you use to determine the total kilowatt output on an unlabeled electric air handler?a. voltmeter & thermometer c. ohmmeter and ammeterb. ohmmeter & voltmeter d. ammeter & voltmeter


33. Which of the following occurs when a heatpump defrosts?a. refrigerant cycle reverses to

cooling, indoor fan stops and defrost relay energizes

c. defrost relay energizes, compressor stops, and supplemental heat energizes

b. compressor stops, supplemental heat energizes, and outdoor fan stops

d. refrigerant cycle reverses to cooling, outdoor fan stops, and supplemental heat energizes if available


34. On a new start-up of a heatpump, in the heating mode, the unit will not accept the entire rated charge due to excessive discharge pressure. What is the most likely cause?a. improper refrigerant vapor line

sizec. insufficient air flow across the

outdoor coilb. improper liquid line size d. insufficient air flow across the

indoor coil


35. A TXV equipped air-conditioner is experiencing low superheat, high suction pressure and excessive compressor sweating. What is the most likely cause?a. power element lost its charge c. evaporator coil is dirtyb. sensing bulb is loose d. undercharged


36. A four (4) burner gas furnace is experiencing low flame height on all of the burners. What is most likely the problem?a. low manifold pressure c. oversized orificesb. flame impingement d. low primary air


37. On a call for heat. a spark-type ignition furnace experiences spark, pilot lights, no further action. What is most likely happening?a. air switch did not close c. improper primary airb. improper sequence of ignition d. inadequate flame signal


38. The suction pressure of an R-410a system at the service valve is measured at 132 PSIG. The line temperature at the same point is 56F. What is the superheat?a. 20F c. 15Fb. 10F d. 45F


39. An R-22 air-conditioner is operating with a liquid line pressure of 211 PSIG and liquid line temperature of 105F. What is the amount of sub-cooling?a. 0F c. 15F

b. 10F d. 20F


40. You find an iced over evaporator coil and the blower motor is hot and cycling on and off. The problem is most likely:a. a faulty motor or capacitor c. capillary restrictionb. undercharge d. dirty condenser


41. On a call to a heatpump in the cooling mode, the compressor runs but the outdoor fan does not. The fan motor and capacitor are determined to be okay. What is most likely?a. heat relay c. reversing valveb. contactor d. defrost control


42. A furnace with four heaters rated 5KW at 240 VAC is getting only 208 VAC. What is the effect on the furnace?a. increase BTUH output c. no decrease if the heaters are

connected in parallelb. no decrease if the heaters are

connected in seriesd. BTUH output will be reduced


43. On start-up of a new heatpump, the unit heats satisfactorily but will not cool. The likely cause isa. outdoor check valve not closing c. indoor check valve openb. indoor check valve closed d. outdoor metering device is not

metering


44. In the heating mode, which of the following would contain high pressure, superheated vapor?a. suction line from reversing

valve to compressorc. liquid line from indoor coil to

outdoor coilb. discharge line from compressor

to reversing valved. outdoor coil


45. In systems with TXV's on both indoor and outdoor coils, what purpose is served by the check valves?a. bypass indoor TXV in heating

and outdoor TXV in coolingc. bypass both outdoor and indoor

TXV's in coolingb. bypass outdoor TXV in heating

and indoor TXV in coolingd. bypass both outdoor and indoor

TXV's in heating


46. In the heating mode, liquid refrigerant can be found in:a. suction line from indoor coil to

outdoor coilc. the reversing valve

b. the compressor d. liquid line from indoor coil to outdoor coil


47. A room to room load calculation is necessary to:a. determine supply and return grill

locationsc. air distribution

b. return air duct location d. velocity requirements


48. An often overlooked adjustment on new systems is:a. heat anticipator c. high limit switchb. air pressure switch d. return air damper

ANSWER: A

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49. Before connecting gauges to stem type (rotolok) service vales, what position should the valves be before removing the caps?a. front seated and cracked c. back seatedb. mid-seated d. completely front seated


50. An oversized air-conditioner could result in:a. high superheat c. high condenser pressureb. excessive humidity d. increases evaporator pressure


51. After new refrigerant piping has been installed and a leak check performed. the system should be evacuated to:a. 30 inches c. 500 microns or lessb. 29 inches d. 1000 to 1500 microns


52. On a service call to a new oil furnace, after resetting the primary control, the unit ignites and runs for approximately 45 seconds then stops. What is the most likely problem?a. dirty or faulty CAD cell c. wrong nozzle sizeb. excessive oil pressure d. closed primary safety switch


53. The primary purpose for a lock-out on an oil burner ignition control is to prevent:a. excessive fuel build up c. burner short cyclingb. furnace overheating d. damage to the ignition control

system

ANSWER: A


54. Which of the following is most important for proper vent operation?a. sufficient return air c. sufficient conditioned airb. adequate combustion air d. adequate supply air


55. An electronic air cleaner should be wired to operate:a. only when the humidifier is

runningc. constantly

b. only when the furnace blower is operating

d. only on a call for heat


56. On a service call to a new oil furnace, you find the pump pressure to be 50 PSIG. What, if anything should yo do?a. increase the pump pressure c. reduce the pump pressureb. add a new fuel filter d. no action needed


57. On a call to a straight cooling unit You find: head pressure above normal, temperature rise across the coil is 42F and sub-cooling is 5F. What is the probable cause?a. dirty outdoor coil c. clogged liquid line drierb. clogged indoor air filter d. refrigerant overcharge


58. What is the purpose of a gas supply line drip leg?a. allows for the expansion of the

gasc. drain condensation from the

evaporator coilb. remove condensation from the

heat exchangers of high efficiency furnaces

d. prevent contamination from entering the gas valve


59. When determining proper supply wire size, you must consider:a. voltage the unit is supplied with c. rating plate ampacityb. minimum circuit ampacity and

length of the wired. rating plate current only


60. Which of the following is a safety concern when positioning a gas furnace?a. adequate gas supply c. clearance from combustible

materialsb. availability of a flue within 2

feetd. distance from the circuit breaker


61. Which of the following could cause evaporator flooding on a capillary tube equipped system?a. low airflow through the

evaporatorc. excessive evaporator airflow

b. low outdoor ambient d. high indoor load


62. In the cooling mode of piston equipped heatpumps, the outdoor piston will be in the:a. bypass position c. metering positionb. front-seated position d. vertical position


63. The indoor coil frosts on start up of a new air-conditioner. Which of the following could be the cause?a. overcharge c. low indoor airflow

b. restricted suction drier d. excessive indoor airflow


64. On a call for cooling, with 230VAC supplied, T1 and L1 close, T2 and L2 do not make contact. What voltage readings would you get?a. 230VAC between T1 & L1 c. 230VAC between L1 & L2b. 230VAC between T2 & L2 d. 230VAC between R & C


65. To determine proper heat anticipator settings, measure the currenta. on the R wire c. on the C wireb. on the W wire d. on the G wire


66. When checking compressor motor windings, the ohmmeter should be set on what scale?a. RX1 c. RX1Kb. RX100 d. RX10K


67. To remove non-condensables, connect the vacuum pump toa. both high and low sides c. high side onlyb. low side only d. suction only


68. On start-up, a heatpump thermostat should be checked to see thata. first stage operates the

compressor and second stage operates the reversing valve

c. first stage operates the airhandler and second stage operates the compressor

b. first stage operates the compressor and second stage

d. first and second stage operate different stages of auxiliary heat

operates the auxiliary heat


69. The most accurate method of controlling refrigerant flow over a wide range of loads is to usea. a capillary tube c. use an automatic expansion

valveb. use a thermostatic expansion

valved. use a metering orifice


70. Which of the following could cause high discharge pressure in a cooling system?a. dirty condenser coil c. dirty evaporator coilb. low charge d. liquid line restriction


71. Manufacturer's requirements for venting "90+" furnaces include, size of the vent, number of elbows, venting materials anda. distance to combustibles c. temperature riseb. length of vent d. direction of air flow


72. The most important advantage of using higher silver content alloys when brazing is thata. the joint is stronger c. the joint will not corrodeb. less heat is required d. flux is not required


73. On a split-system air-conditioner, increasing the evaporator airflowa. removes less humidity c. increases the temperature

difference across the coilb. causes frost to build up on the

coild. removes more humidity


74. Step opening gas valves are valves that opena. at a partial rate, then change to

full rate c. at full rate then change to a

partial rateb. and close at the same time

intervalsd. to one burner at a time


75. Which of the following could indicate an overcharge on a fixed meteringair-conditioner?a. low head, low suction c. excessive superheatb. high head, high suction d. low sub-cooling


76. What is the primary reason for a low ambient control?a. controls indoor blower during

mild weatherc. maintains minimum discharge

pressureb. shuts off the compressor when

outdoor temperature rises above 35F

d. switches condenser fan to high speed


77. Which of the following are needed to determine superheat?a. discharge line temperature and

suction line temperaturec. liquid pressure and temperature

b. air temperature difference across evaporator

d. suction pressure and temperature

ANSWER: DPOINTS: 0 / 1

FEEDBACK:

78. On a service call to an oil furnace, what safety precaution should the technician make before firing the furnace?a. disconnect electricity c. check oil pressureb. check for grounded electrodes d. check for liquid oil in the

combustion chamber


79. Which of the following are needed to check oil furnace efficiency?a. net stack temperature and CO2

concentrationc. net stack and indoor temperature

b. net stack temperature and CO d. stack temperature and fuel pressure


80. When using hard drawn tubing, which of the following should be used to fabricate a 90 bend?a. a 90 flared union c. a spring benderb. a 90 compression elbow d. a long radius 90 elbow


81. What is the maximum fill level for a refrigerant recovery cylinder?a. 50% of name plate capacity c. 70% of rated capacityb. 60% of name plate d. 80% of rated capacity


82. If the pressure switch on an induced draft furnace fails to close, the most likely cause isa. a blockage in the vent system c. manifold pressure too lowb. circulating blower is on the

wrong speedd. manifold pressure too high

ANSWER: A


83. To energize the electric strips in a heatpump the technician may need toa. check the anticipator current c. jumper or adjust outdoor

thermostatsb. turn thermostat all of the way

downd. check auxiliary heat light on

thermostat


84. Lower than normal voltage at the compressor contactor coil can be caused bya. thermostat wire too small c. higher that normal supply

voltageb. oversized control transformer d. incorrect capacitor


85. When check flame current, the meter should be set fora. AC milliamps c. AC microampsb. DC milliamps d. DC microamps


86. The common terminal on heatpump thermostats is used fora. power the outdoor thermostats c. stabilize the voltage in the

cooling cycleb. power shunt type anticipator and

indicator lightsd. add power to the back-up

heaters


87. The vent safety switch installed in the draft hood areaa. protects the furnace from

overheating if the limit failsc. shuts down the gas valve if the

furnace is spilling vent productsb. automatically increases blower

speed if the furnace overheatsd. protects the heat exchanger from

damage


88. For safety, when checking an electric furnace, after turning off the unit disconnect you should checka. ohms from L1 to ground c. resistance of the sequencersb. voltage on the line side of the

disconnectd. voltage on the load side of the

disconnect


89. Velocity in a 9" X 8" duct is measured at 800 FM.hat is the air volume?a. 144 CFM c. 800 CFMb. 400 CFM d. 1600 CFM


90. Refrigerants can become toxic when they contacta. contaminated oil c. a high heat sourceb. water or moisture d. nitrogen


91. Velocity pressure is a. total pressure minus static

pressurec. static pressure plus total

pressureb. static pressure minus differential

pressured. static pressure times duct cross

sectional area


92. Manifold gas pressure on a single stage propane system should normally bea. 3.5" wc c. 10" wcb. 7" wc d. 13" wc

ANSWER: C


93. Which of the following is not an accepted method of leak detection?a. R-22 and compressed air c. R-22 and nitrogenb. R-22 and an inert gas d. nitrogen only


94. The purpose of the National Fuel Gas Code is toa. provide a material list for a gas

installationc. provide minimum safety

requirements for a gas appliance/installation

b. identify the number of safety devices needed in a gas installation

d. satisfy the local building code


95. What happens to static pressure after sealing a leaky duct system?a. increases c. changes to total pressureb. decreases d. changes to velocity pressure


96. What instrument is used to measure duct velocitya. pyrometer c. hygrometerb. anemometer d. tachometer


97. What is the biggest disadvantage of using flex duct as compared to sheetmetal duct?a. less pressure drop c. more restrictionb. more fittings required d. increased installation time

ANSWER: CPOINTS: 0 / 1

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98. Partially restricting the return side of a duct system will cause the amperage of a PSC blower toa. decrease c. increase b. stay the same d. hunt up and down


99. What is the biggest safety hazard when using A1 refrigerantsa. they are poisonous c. they are lighter than airb. suffocation d. they ignite in air


100. A refrigerant cylinder weighs 36 Lbs. The cylinder alone weighs 6 lbs. A technician uses 1/6 of the refrigerant on one unit. He then uses 10 lbs on another job. How much refrigerant is left in the cylinder?a. 14 lbs c. 16 lbsb. 15 lbs d. 20 lbs

ANSWER: BPOINTS: 0 / 1

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