Topics: All categories in the pool
1: Which oil is hydoscopic?
- polyolester
- mineral
- animal
- SW30
2: What type of pressure relief device is used on a CO2 system?
- Fusible plug
- Glove valve
- Rupture disk
- Gate valve
3: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
- 77F
- 70F
- 58F
- 32F
4: Class T machine room
- shall have refrigerant leak detecting systems installed inside and outside the room
- shall include closets used for setting equipment
- has no flame producing apparatus permanently installed
- shall have remote controls to stop the action of the refrigerant compressor
5: Walls and doors of a machinery room shall be at least _____ hour(s) fire rated.
- 1
- 2
- 5
- 3
6: Which of the following types of oils are hygroscopic?
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene mineral
- both a and b
7: The amount of heat required to raise the temperature of 1 lb of water 1F is?
- 1 Therm
- 1 BTU
- 1 Kelvin
- The rate of conduction
8: Methyl Chloride is a halogenated refrigerant and should not come in contact with
- aluminum
- zinc
- magnesium
- all of the above
9: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
10: The outer portion of shell of the compressor used on low-pressure chillers is called the
- suction
- nozzle
- volute
- baffle
11: What is Trichlorotrifluoromethane?
- R-13
- R-113
- R-11
- R-12
12: If a liquid receiver is designed to receive the refrigerant charge during a pumpdown procedure, it shall have the capacity to
- receive the pumpdown charge
- release the charge when the pressure exceeds 310 psig or higher
- Pumpdown procedures are not allowed with systems containing liquid recievers
- hold up to 110% of the pumpdown charge
13: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
- 18
- 24
- 10
- 15
14: What instrument is used to measure very high resistance?
- voltmeter
- meg ohmmeter
- ammeter
- tape measure
15: The reversing valve is commonly used
- on multiple compressor systems
- on commercial system that involve two different temperatures
- when the code requires a check valve
- on all heat pumps
16: The proper location for an oil separator is between the
- compressor and condenser
- receiver and metering device
- evaporator and compressor
- condenser and receiver
17: What chemical in the refrigerant set off the leak detection alarm?
- Fluorine
- Chlorine
- Both A and B
- none of the above
18: Mercury was used in thermometers primarily because it
- never freezes
- expands uniformly
- was inexpensive
- vaporizes at very high temperatures
19: How much refrigerant can be stored in a mechanical room outside of the system?
- 200
- 330
- 150
- 100
20: When testing systems using non-positive displacement compressors, the entire system shall be considered for test purposes as the low side.
- True
- False
21: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Saturated temperature
- Critical temperature
- Wet bulb temperature
- Dry bulb temperature
22: While water is evaporated in an evaporative condenser the impurities which were in the water are
- remain in the air
- blown to the atmosphere by the fan
- washed out of the air by the spray pump
- accumulate in the sump water
23: Three-phase motors have what type of windings?
- three start windings
- one start winding and one run winding.
- three run windings
- three run windings and 3 start windings
24: Relief valves are rated in
- gallons of water per minute
- gallons of water per hour
- pounds of air per minute
- pounds of air per hour
25: What is the refrigerant dichlorodifluoromethane?
- R-22
- R-12
- R-123
- R-134A