Topics: All categories in the pool
1: What section of ASHRAE-15 governs pressure vessels?
- Section 9 ASHRAE-15 ASME VIII unfired
- Section 6 ASHRAE-34 ASME VIII unfired
- OSHA
- Section 7 ASHRAE-15 ASME VIII fired
2: Where can 50/50 solder be used on?
- suction line
- liquid line
- discharge line
- none of the above
3: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
- 600F
- 800F
- 1000F
- 700F
4: Halogenated refrigerants cannot be used with what material?
- Aluminum
- Copper
- Magnesium alloy
- Stainless steel
5: Ammonia shall be discharged into ____________ or a tank containing one gallon of water for every pound of ammonia.
- the atmosphere
- a de-pressurized recovery tank with a silver top and yellow bottom
- a tank containing two pounds of a water/lithium bromide mix for every pound of ammonia
- All of the above
6: A high side float is a
- float type valve that controls the amount of refrigerant stored in the receiver
- float type valve that controls the crankcase oil level
- metering device used on critically charged systems that controls the level of the liquid refrigerant in the high pressure side of the system.
- float type switch that stops the compressor when the pressure on the high side becomes too high
7: A R-22 system running with a condensing temperature of 110F and a 40F evaporator temperature will read pressures of ____ on the high side and ____ on the low side.
- 455 psig, 185 psig
- 350 psig, 120 psig
- 226 psig, 68 psig
- 257 psig, 77 psig
8: A 24 volt transformer with a 240 volt primary can handle how many amps?
- 10 amps
- 24 amps
- 20 amps
- There isn't enough information to answer.
9: Machinery rooms must be vented to ______?
- basement
- outdoors
- unoccupied spaces
- neutralizing tank
10: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- the aggregate of the high side and low side
- the low side
- the high side
- 2.5 times the design pressure
11: A positive displacement compressor is
- a compressor in which the increase in pressure is attained by changing the internal volume of the compression chamber
- where the compressor's suction pressure and the compressor;s discharge pressure is more than 50 PSI
- is a reciprocating type compressor with 2 or more pistons
- a compressor in which the increase in pressure is attained by changing the internal pressure of the compression chamber
12: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- Place sign, check for leaks, and insulate suction line
- Make sure its compatible, notify owner, and notify AHJ.
- you can never change refrigerants
- Nothing must be done
13: What type of relief valve is used on a CO2 system?
- gate valve
- fusible plug
- glove disc
- rupture disc
14: In a low temperature refrigeration system, the benefit of the system using P.A.G. oil is
- it is hydroscopic
- it traps moisture
- viscosity
- all of the above
15: While the system is operating, the discharge line should be
- too hot to hold by hand
- room temperature
- 10-15F warmer than ambient
- at the same temperature as the crankcase
16: Pressure vessels having design pressures of 15 psig or less shall have the strength to withstand at least ______times the design pressure.
- 2.0
- 3.0
- 5.5
- 2.5
17: There can be no airflow from an occupied space through a machine room unless what?
- System is high velocity
- System is ducted and sealed
- Duct is not located in the ceiling
- None of the above.
18: What is specific heat?
- measured heat
- heat required to raise the temperature of 1lb of a substance 1 degree
- the specific heat required to change the state of one cubic foot of air to steam
- none of the above
19: An example of direct system is
- rooftop unit
- chiller
- absorber
- none of the above
20: What is R-22?
- HFC
- Chlorodifluoromethane
- CCFCM
- Chlorofluoromethane
21: Which of the following is NOT a positive displacement compressor?
- screw
- centrifugal
- reciprocating
- scroll
22: Low ambient controls are used when
- always
- economizers are used
- when systems run all year round
- on air conditioning systems only
23: What is used to check very low air pressures in air conditioning duct?
- Manometer
- Anemomter
- Barometer
- Vacuum gauge
24: In an electrical circuit, what is potential measured in?
- Herys
- Amps
- Ohms
- Volts
25: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
- CPR valve
- EEV
- Solenoid valve
- EPR valve