Maintenance And Troubleshooting Trivia Quiz!
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- 1.To safely check an electrical component for continuity or resistance, you would turn
- A.
On the power and disconnnect at least one lead from the meter
- B.
Off the power and disconnect at least one lead from the meter
- C.
On the power and disconnect at least one lead from the component
- D.
Off the power and disconnect at least one lead from the component
- 2.Which thermostat terminal passes power to the heat relay?
- A.
R
- B.
G
- C.
W
- D.
Y
- 3.Which thermostat terminal passes power to the indoor fan?
- A.
R
- B.
G
- C.
W
- D.
Y
- 4.Which fan circuit contacts must be closed to pass power to the fan motor?
- A.
Fan realy
- B.
Fan speed relay
- C.
Evaporator relay
- D.
Condenser relay
- 5.The three components that operate in the cooling mode are the
- A.
Compressor, the evaporator, and the outdoor fan
- B.
Indoor fan, the compressor, and the outdoor fan
- C.
Comrpessor, the indoor fan, and the defrost cycle
- D.
Outdoor fan, the indoor fan, and auxiliary heat
- 6.Most manufacturers illustrate the wiring in their equipment through the use of
- A.
Pictoral and line diagrams
- B.
Line and sectional diagrams
- C.
Sectional and pictoral diagrams
- D.
Sectional and enhanced diamgrams
- 7.You turn the indoor fan switch on a thermostat to the FAN ON position. When you do, the indoor fan motor does not come on. A possible cause of the problem is that there is
- A.
Control voltage
- B.
No control voltage
- C.
Too much control voltage
- D.
Not enough control voltage
- 8.You use your volt-ohm-milliammeter to check a transformer. You find it has an open. In this situation, the probable trouble is
- A.
No control voltage
- B.
A burned transformer
- C.
No power to the G terminal
- D.
A wire burned off the compressor
- 9.On a trouble call, you determine that voltage is present from R to Y at the thermostat but no voltage is present at the condenser contactor. In this situation, you would suspect that the
- A.
R wire is broken
- B.
Contacts are broken
- C.
Y wire is broken
- D.
R and Y wires are both broken
- 10.Which terminals would you use to determine why a thermostat does not pass power to the relays when a split-system air-conditioner unit is in the cooling mode?
- A.
R, G, & W
- B.
R, G, & Y
- C.
V, B, & W
- D.
V, B, & Y
- 11.After you have disabled a motor disconnect, you lock and tag the panel. After this, you should be sure to keep the only key
- A.
At the shop
- B.
On your person
- C.
With your crew leader
- D.
With your shop supervisor
- 12.Mechanical motor problems normally occur at the
- A.
Pulley or belt drive
- B.
Bearings or the shaft
- C.
Pulleys or the shafts
- D.
End bells or ball bearings
- 13.Most assemblies are held on the motor shaft by
- A.
Setscrews
- B.
Snap rings
- C.
Lock pins
- D.
O-rings
- 14.If the motor drive pulley and the driven pulley are out of line, strain will be imposed on the
- A.
Starting circuit
- B.
Fram mount
- C.
Motor air system
- D.
Shafts' drive mechanism
- 15.A short circuit will occur in the windings of a motor when the conductors in the windings
- A.
Touch each other
- B.
Expand and contract
- C.
Pull apart from each other
- D.
Create a high amperage draw
- 16.To check for a short circuit from a motor winding to ground, you would use
- A.
A voltmeter
- B.
An ohmmeter
- C.
An anmeter
- D.
A clamp-on meter
- 17.A run capacitor on an eletric motor is constructed as a
- A.
Metal can
- B.
Paper can
- C.
Plastic can
- D.
Bakelite iron can
- 18.A start capacitor on an eletric motor is constructed as a
- A.
Wet type
- B.
Dry type
- C.
Round type
- D.
Square type
- 19.The motor problems that can occur inside a hermetic compressor are
- A.
A blown fuse, closed circuit, and grounded circuit
- B.
A closed circuit, short circuit, and a blown fuse
- C.
A grounded circuit, closed circuit, and a short circuit
- D.
An open circuit, short circuit, and grounded circuit
- 20.A motor that has a bad run capacitor
- A.
Will not start
- B.
May run at normal speed
- C.
May run at a lower-than-normal speed
- D.
Will run at a higher-than-normal speed
- 21.What type of electrical problems will a hermetic compressor have?
- A.
Open circuit
- B.
Short circuit
- C.
Grounded circuit
- D.
All of the above
- 22.A single-phase condition in a three-phase motor can be caused by
- A.
A defective start capacitor
- B.
A burned motor
- C.
A blown fuse
- D.
A closed circuit
- 23.What is the possible cause when a motor will not start, hums and trips on overload?
- A.
Incorrect overload switch
- B.
Open disconnect switch
- C.
Incorrect power supply
- D.
Open fuse or breaker
- 24.The temperature range of a refrigeration system depends upon the
- A.
Product being refrigerated
- B.
Condensing temperature
- C.
Size of the compressor
- D.
Ambient temperature
- 25.To maintain 75 percent humidity in a refrigeration system with a temperature range of 25 to 45*F, the appropriate coil-to-air temperature would be
- A.
8 to 12*F
- B.
10 to 14*F
- C.
12 to 16*F
- D.
16 to 22*F
- 26.The box temperature for high-temperature refrigeration system start at
- A.
30*F
- B.
45*F
- C.
50*F
- D.
65*F
- 27.When the compressor is off and the system is up to the highest point of its operating range, the evaporator coil pressure should correspond to the
- A.
Compressor pressure
- B.
Condenser pressure
- C.
Air tmeperature in the box
- D.
Air temperature at the condenser
- 28.When the temperature of a refirgerateed space goes down, the compressor will have
- A.
Less capacity because the suction gas gets thinner
- B.
More capacity because the suction gas gets thinner
- C.
Less capacity because the suction gas gets more dense
- D.
More capacity because the suction gas gets more dense
- 29.What condensing temperature is normally maintained to obtain adequate pressure drops across an expansion valve?
- A.
95*F
- B.
105*F
- C.
115*F
- D.
125*F
- 30.What is the normal temperature difference between the inlet and the outlet water on s wastewater water-cooled condenser?
- A.
25*F
- B.
20*F
- C.
15*F
- D.
10*F
- 31.What is the most likely problem if the temperature difference between the inlet and the outlet water in a water-cooled is lower than normal?
- A.
Ther water flow is sifficient
- B.
There is too much water flow
- C.
There is not enough water flow
- D.
The cooling tower fan just cycled on
- 32.What is the normal maximum reduction of temperature in a cooling tower water if the ambient wet-bulb temperature is 85*F?
- A.
72*F
- B.
75*F
- C.
78*F
- D.
81*F
- 33.What conditions are an indication of an overcharge in a system that is not equipped with an automatic expansion valve?
- A.
Low suction pressure and high discharge pressure
- B.
High suction pressure and low discharge pressure
- C.
Low suction pressure and low discharge pressure
- D.
High suction pressure and high discharge pressure
- 34.The most probable causes of an inefficient evaporator are
- A.
A dirty coil and a fan running too slow
- B.
A dirty coil and a high suction pressure
- C.
Too much airflow and a high suction pressure
- D.
Too much airflow and a fan running too slow
- 35.What conditions are an indication of a low charge in a system that is not equipped with an automatic expansion valve?
- A.
Low suction pressure and high discharge pressure
- B.
High suction pressure and low discharge pressure
- C.
Low suction pressure and low discharge pressure
- D.
High suction prssure and high discharge pressure
- 36.If the condenser in a refrigeration system cannot remove the heat from the refrigerant, the
- A.
Suction pressure will decrease
- B.
Discharge pressure will increase
- C.
Liquid-line temperature will decrease
- D.
Suction line will frost back to the compressor
- 37.When a partial restriction occurs in the liquid line, the point of the restriction will act like
- A.
An evaporator
- B.
A condenser
- C.
A compressor
- D.
An expansion device
- 38.A compressor that is not pumping to full capacity will have
- A.
High suction and low head pressure
- B.
High suction and high heah pressure
- C.
Low suction and low head pressure
- D.
Low suction and high head pressure
- 39.You have removed and recovered the refrigerant from a system and solder repaired a leak. Before you recharge the unit, you must first perform
- A.
A 4-hour standing vacuum test
- B.
An operational test of the system
- C.
Recurring maintenance
- D.
A leak check
- 40.Calculate the discharge pressure for an R–502 system operating at 95*F outside ambient temperature.
- A.
95*F + 15*F = 110*F and 245 psig
- B.
95*F + 20*F = 115*F and 265 psig
- C.
95*F + 25*F = 120*F and 286 psig
- D.
95*F + 30*F = 125*F and 301 psig
- 41.
- A.
Defrost is terminated by the time clock.
- B.
The unit operates with excessive head pressure
- C.
The unit operates with excessive suction pressure.
- D.
Manually initiated defrost is terminated by the temperature sensing device
- 42.Which is designed to stop the defrost cycle of a low-temperature walk-in?
- A.
Low-pressure motor control
- B.
High-pressure safety switch.
- C.
Termination switch.
- D.
Oil pressure switch.
- 43.When the thermal bulb of an expansion valve is loose from the suction line, you would expect the
- A.
Suction line to be warmer than normal
- B.
Suction line to be colder than normal
- C.
Discharge line to be warmer than normal.
- D.
Discharge line to be colder than normal
- 44.What problems can a high-efficiency water filtration system cause for an ice machine?
- A.
None, these systems are mandatory.
- B.
The system can increase the conductivity of the water.
- C.
The system can decrease the conductivity of the water.
- D.
None, these systems do not change the conductivity of water and cause no problems.
- 45.A refrigerator may have condensation (sweat) on the outside of the cabinet if the
- A.
Mullion heater is defective.
- B.
Defrost time clock is defective
- C.
Defrost termination switch is defective.
- D.
Evaporator fan motor is defective
- 46.When an exact replacement compressor for a refrigerator cannot be obtained, you would gather all data from the
- A.
Compressor nameplate only
- B.
Refrigerator nameplate only.
- C.
Refrigerator nameplate and draw a diagram of the compressor lines and mounting
- D.
Compressor nameplate and draw a diagram of the compressor lines and mounting
- 47.You should never use hand tools in a
- A.
Hot electrical panel
- B.
Cold electrical panel
- C.
Cold package air conditioner
- D.
Hot package air conditioner
- 48.You can reduce the danger involved in attaching high-pressure gauges on a manifold by stuttin off the
- A.
Refrigerant and allow to cool
- B.
High side and allowing the pressures to equalize
- C.
Valves and allowing the pressures to equalize
- D.
Unit an allowing the pressures to equalize
- 49.To verify that the refrigerant is boiling at the correct temperature for the low side of the system at a given load condition, you would use
- A.
The high-side gauge readings
- B.
The low-side gauge readings
- C.
Ultralow pressure gauge readings
- D.
All of the above
- 50.To check the relationship of the condensing refrigerant to the ambient air temperature, you would use
- A.
The high-side gauge readings
- B.
The low-side gauge readings
- C.
Ultralow pressure gauge readings
- D.
All of the above
- 51.If there is an internal refrigerant leak from the high-pressure side to the low-pressure side of a system, the discharge gas temperature will
- A.
Equalize to the system
- B.
Stay the same
- C.
Go down
- D.
Go up
- 52.What method would you use to measure the amount of refrigerant in a condenser?
- A.
Superheat method
- B.
Supercooling method
- C.
Subcooling method
- D.
Condensing method
- 53.You are preparing to troubleshoot a system for an electrical problem. Before you start to troubleshoot the components, you would verify that the
- A.
Power supply is energized and the voltage is correct
- B.
Connections are mechanically and electrically sound
- C.
Contacts on all relays are clean and free to move
- D.
Wires are all electrically insulated and tight
- 54.You make a continuity check on a compressor. The check indicates that the common circuit in the compressor is open. You feel the compressor dome and it is very hot. In this situation, you would suspect that the
- A.
Capacitor is open
- B.
Run windings are open
- C.
Start windings are open
- D.
Internal overload protector is open
- 55.You are troubleshooting a compressor that repeatedly trips the circuit breaker. The most likely problem is that the compressor motor
- A.
Has an open winding
- B.
Has a grounded winding
- C.
Centrifugal switch is open
- D.
Centrifugal switch is closed
- 56.The function of the indoor coil on a heat pump unit is to
- A.
Be a condenser in summer and an evaporator in winter
- B.
Be an evaporator in summer and a condenser in winter
- C.
Act only as an evaporator
- D.
Act only as a condenser
- 57.When does the outdoor unit on a heat pump act as an evaporator?
- A.
Fall
- B.
Spring
- C.
Summer
- D.
Winter
- 58.What is used to supplement the unit when the outdoor temperature drops to a point where the heat pump becomes inefficient?
- A.
Auxiliary refrigerant
- B.
Auxiliary forced air
- C.
Auxiliary heat
- D.
All of the above
- 59.What type of switch is used to prove there is water flow in both the chilled-water and condenser water circuits?
- A.
Flow
- B.
Pressure
- C.
Water-sending
- D.
Velocity-sending
- 60.Before you start a reciprocating chiller, you must ensure that the oil level is at
- A.
One-eighth to one-fourth of the sight glass
- B.
One-fourth to three-fourths of the sight glass
- C.
One-fourth to one-half of the sight glass
- D.
Three-fourths to one-half of the sight glass
- 61.Before you start the compressor on a centrifugal chiller, you must verify there is oil pressure. To do this, you would start the oil
- A.
Pump in manual
- B.
Sump in manual
- C.
Pump in auto
- D.
Sump in auto
- 62.An oil sample from the crankcase of a centrifugal compressor should be sent to an oil laboratory on
- A.
A monthly basis
- B.
A quarterly basis
- C.
A semiannual basis
- D.
An annual basis
- 63.After you have cleaned the tubes in a condenser, how would you check their condition for defects?
- A.
Pressure test
- B.
Water flow test
- C.
Eddy-current check
- D.
Megger current check
- 64.What should be done to water chillers during the winter?
- A.
Completely filled with antifreeze
- B.
Completely filled with water
- C.
Completely drained
- D.
All of the above
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