Topics: All categories in the pool
1: A compressor in which the increase in vapor pressure is attained without changing the internal volume of the compression chamber is called
- negative displacement compressor
- non-positive displacement compressor
- non-volumetric displacement compressor
- neutral chamber-type compressor
2: The absorber shell contains the
- condenser and the absorber
- condenser, the evaporator, and the generator
- condenser and the generator
- evaporator and the absorber
3: Control systems can be classified by
- safety
- tonnage of system
- economy of operation
- source of power
4: When air is ducted through a machine room that services occupied space, What must be done?
- Insulated and cross broke
- Ducted and sealed
- Welded and seamed.
- Flanged and gasketed
5: A moisture indicator must
- change color when exposed to moisture
- be sight side up
- be filled with liquid
- be yellow
6: What section governs pressure vessels?
- Section 1 ASHREA 15 ASME fired
- Section ASHREA 34
- OSHA
- Section 8 ASHREA 15 ASME unfired
7: 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
8: The location of a thermal bulb of a TXV affects
- subcooling
- the amount of liquid in the condenser.
- the amount of liquid refrigerant in the evaporator
- the amount of liquid returning to the compressor
9: A relief valve discharge capacity is rated in
- PSIA
- PSIG
- Pounds of air per minute.
- temperature minus pounds of air per second divided by release rate squared
10: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
11: Which refrigerant was still able to be vented to the atmosphere after July 1, 1992?
- R-11
- R-12
- R-113
- R-22
12: How are a compressor and condenser fan wired?
- parallel
- parallel-series
- series
- series-parallel
13: Where would the EPR valve be located on a multiple evaporator system?
- outlet of low temperature evaporator
- outlet of the liquid line
- inlet of the low temperature evaporator.
- outlet of high temperature evaporator
14: A high side float is a
- float type valve that controls the amount of refrigerant stored in the receiver
- float type switch that stops the compressor when the pressure on the high side becomes too high
- 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.
15: Low-side system leaks in a low-pressure chiller will often result in
- system refrigerant leaking from the system
- water being pulled into the system
- nitrogen leaking out of the system.
- air being pulled into the system
16: To determine the pump size needed for an open cooling tower system, the following must be known,
- GPM and unbalanced head and friction head
- GPM, pipe size, and equivalent head.
- GPM and friction head
- GPM and balanced head and friction head
17: one BTU equals
- 31.4 hp
- 3.41 hp
- Pi
- 12,000 hp
18: A device used to measure small pressure differences is the
- pyrometer
- phsycometirc
- manometer
- anemometer
19: The reversing valve is commonly used
- on commercial system that involve two different temperatures
- on all heat pumps
- when the code requires a check valve
- on multiple compressor systems
20: When releasing a hydrogenated hydrocarbon refrigerant to the atmosphere, ample ventilation must be provided and
- no flames shall be permitted
- explosion precautions must be taken
- gas masks must be worn
- the owner shall be informed
21: Name a reason that does not cause reduced condenser air quantity
- Dirty fan blades
- High ambient temperature
- Dirty Coil
- Prevailing winds
22: Two capacitors are wired in parallel. One capacitor has a value of 15uf. The other has a value of 25uf. What is the total value supplied?
- 20 uf
- 40 uf
- 25 uf
- 15 uf
23: Low pressure systems have what kind of compressor?
- Rotary
- Reciprocating
- Scroll
- Centrifugal
24: An azeotropic refrigerant is
- a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
- a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
- a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
- none of the above
25: Liquid refrigerant R-22 enters an evaporator at 50.2 psig, 20F and leaves 37F, its pressure as it leaves will be
- 70.8 psig
- 50.2 psig
- 43.3 psig
- 66.1 psig