Topics: All categories in the pool
1: The critical temperature of a refrigerant gas occurs when
- the gas returns to a liquid
- the gas is no longer saturated
- any increase in pressure will not liquefy the gas
- any decrease in pressure will cause condensation
2: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the
- low side of the system
- high side float assembly
- cap tube
- none of the above
3: one BTU equals
- 31.4 hp
- 3.41 hp
- Pi
- 12,000 hp
4: 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.
- 50
- 15
- 55
- 75
5: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 80 ohms
- 27 ohms
- 104 ohms
- 71 ohms
6: Halogenated refrigerants cannot be used with what material?
- Stainless steel
- Aluminum
- Copper
- Magnesium alloy
7: The reversing valve is commonly used
- when the code requires a check valve
- on multiple compressor systems
- on all heat pumps
- on commercial system that involve two different temperatures
8: On cooling towers, what causes the condenser water to drop
- tower fans
- ambient temperatures
- sensible heat
- evaporation of the water droplets
9: When using nitrogen for brazing, the pressure should be:
- Very low
- 50-100 psig
- Slightly below atmospheric
- 125 psig
10: What section governs pressure vessels?
- OSHA
- Section 8 ASHREA 15 ASME unfired
- Section ASHREA 34
- Section 1 ASHREA 15 ASME fired
11: Start to Run windings will have what resistance?
- The most resistance value
- All will be at equal values
- Somewhere between the actual start winding and run winding resistance value
- The least resistance value
12: Booster compressors connect to the ____ side of the compressor
- oil side
- vapor
- liquid
- low side
13: The Department that certifies the transportation of refrigerant is the
- EPA
- EPO
- DOT
- RSES
14: Which of the following controllers would you expect to be most sensitive to temperature changes?
- low voltage t-stat
- aquastat
- line voltage t-stat
- immersion controller
15: Foaming of oil in a compressor is most likely to occur
- when the evaporator temperatures are below 32F
- when ambient temperature are low
- at start-up
- when there is insufficient air across the condenser(i.e., dirty coil)
16: Electricity involves the movement of electrons in atoms
- True
- False
17: If the power element of an expansion valve should lose its charge the valve would
- underfeed the evaporator
- overfeed the evaporator
- go closed
- go open
18: What is an egress?
- A valve put on the low side of the system to prevent frosting
- An entrance or exit
- An escape route
- A code violation
19: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
- 2.2
- 1
- 1.5
- 1.2
20: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
- boost voltage
- lift voltage
- run voltage
- pick up voltage
21: What kind of material can't be used on the outlet of a relief valve?
- Copper
- PVC
- Aluminum
- Stainless Steel
22: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
23: What instrument is used to measure very high resistance?
- meg ohmmeter
- voltmeter
- tape measure
- ammeter
24: Liquid refrigerant R-22 enters an evaporator at 50.2 psig, 20F and leaves 37F, its pressure as it leaves will be
- 50.2 psig
- 66.1 psig
- 43.3 psig
- 70.8 psig
25: How many groups of refrigerants are there?
- 7
- 5
- 3
- 1