Topics: All categories in the pool
1: What type of copper is not permitted on refrigeration systems?
- Type N
- Type K
- Type M
- Type L
2: "E" represents _____ in the Watt's law formula.
- amperage
- voltage
- watts
- reactance
3: Materials used in construction and installation materials used in the manufacture or installation of refrigerating equipment shall be suitable for conveying refrigerant and the refrigerant oils and will not deteriorate in the presence of what?
- Moisture and air
- Oil and water
- Air and dirt
- Water and soap
4: Pressure vessels having design pressures of 15 psig or less shall have the strength to withstand at least ______times the design pressure.
- 3.0
- 2.0
- 5.5
- 2.5
5: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 71 ohms
- 27 ohms
- 104 ohms
- 80 ohms
6: A halide torch is most useful with a freon compression system
- to detect refrigeration leaks in piping joints
- to remove from from TXV's and evaporator coils
- to release a sticking valve
- to sweat flanges on the refrigeration piping
7: Before replacing a seized compressor, the _______ should be determinded.
- type of refrigerant
- current draw
- cause of seizure
- designed head pressure
8: Color is important in oil because
- it indicates the viscoisty.
- can tell us something about the refining of oil
- allows you to see into crankcase
- it makes sight glasses easy to read
9: Clearance volume
- is the same on all compressors
- affects compressor capacity
- has no effect on compressor capacity
- varies depending on compressor speed
10: How many refrigerant classifications are there for flammability?
- 2
- 7
- 1
- 3
11: The oil separator is always inserted in the system
- to prevent oil logging
- where it can be easily serviced
- in the discharge line
- in a cool spot
12: Halogen refrigerants are corrosive to which type of metal?
- black iron
- copper
- stainless steel
- magnesium
13: Which refrigerant is lighter than air?
- R-717
- R-11
- R-123
- R-134a
14: Laten heat is associated with a change in state of a refrigerant but not temperature
- True
- False
15: It shall be the duty of the person in charge of the premises on which a refrigeration system containing more than ___ lbs of refrigerant is installed to provide a schematic drawing or panel giving directions for the operation of the system.
- 75
- 50
- 55
- 15
16: "I" represents ____ in the Ohm's law formula.
- capacitance
- amperage
- voltage.
- resistance
17: Sublimation occurs when
- gas is formed directly from a solid
- ice melts and turns to water
- gas is formed from a liquid
- liquid is formed from a gas
18: Suction line oil traps should be installed when the condenser is
- in the basement and the evaporator is on the third floor
- located outside the operates in temperatures below 35F
- more than 100' away from the evaporator
- on the third floor roof and the evaporator is in the basement
19: Direct systems using Group II refrigerants
- shall be installed in Class T machinery rooms
- shall not be used for air condition for human comfort
- shall be installed per instruction of the AHJ
- shall be allowed to be used for human comfort.
20: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- trichlorotrifluoromethane
- ammonia
- methyl chloride
- R-718
21: In a motor, an internal overload might open if
- there's an excess current draw through the motor
- there was a high pressure refrigerant was used for a low pressure system.
- there's an open start winding
- there's a direct short
22: A relief valve shall be located at least ___ above grade.
- 36'
- 15'
- 25'
- 10'
23: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- nothing must be done
- make sure it's compatible, notify owner, notify A.H.J
- place sign, check for leaks, insulate
- you can't change refrigerants
24: A mercury bulb controller is not recommended for
- use where vibration is severe
- line voltage use
- low voltage use
- line or low voltage use
25: R-717 is
- ammonia
- trichloromethane
- water
- carbon dioxide