Topics: All categories in the pool
1: 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.
- 257 psig, 77 psig
- 226 psig, 68 psig
- 455 psig, 185 psig
- 350 psig, 120 psig
2: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
- 9F
- 21F
- 29F
- 11F
3: Doors communicating with outside from a mechanical room must be?
- Steel, approved, weather-stripped
- Self-closing, approved, fire door
- Self-closing, aligned, fire door
- Self-closing, wooden, fire door
4: A room having machinery but no flame producing apparatus permanently installed and operated is considered a
- Class T machinery room
- Class B machinery room
- Class M machinery room
- Class A machinery room
5: How many forces operate a thermostatic expansion valve?
- 1
- 4
- 2
- 3
6: On a single phase motor, when does the start winding cut out?
- 25% of its RLA speed
- 50% of its RLA speed
- 75% of its RLA speed
- 100% of its RLA speed
7: 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
8: Where is an EPR valve located on a multi-evaporator system?
- Suction line prior to the accumulator of the lowest temperature system
- Suction line of the warmest evaporator
- Suction line at the compressor
- Suction line of the coolest evaporator
9: Fusible plugs shall not be used with pressure vessels of
- 15 square feet or less
- 3 cubic feet or more
- 3 cubic feet or less
- 15 cubic feet or more
10: When systems are protected by a high pressure relief device, the compressor's pressure limiting device shall be set at or below ____ % of the operating pressure of the high side relief device.
- 90
- 100
- 80
- 110
11: Ohm's Law indicates Amps X Resistance = ___________.
- Volts
- Current
- Ohms
- Impedance
12: 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
13: Crankcase heaters are energized
- when the compressor is off
- to prevent compressor freeze-up
- while the compressor is running
- to allow easy compressor start-up
14: An example of an "Expendable Refrigerant" is
- lithium bromide
- ammonia
- liquid nitrogen
- liquid oxygen
15: How many gallons of water per pound of ammonia do you need?
- 15
- 5
- 20
- 1
16: High pressure controls should be set no higher than
- 10% of set point
- 25% of set point
- 80% of set point
- 90% of set point
17: 1 HP = ____ Watts?
- 11,239
- 3.1416
- 3,412
- 746
18: Low-side system leaks in a low-pressure chiller will often result in
- air being pulled into the system
- system refrigerant leaking from the system
- water being pulled into the system
- nitrogen leaking out of the system.
19: Atmospheric pressure is equal to
- 29.92" Hg
- 14.7 psia
- 14.7 psig
- both a & b
20: Electricity involves the movement of electrons in atoms
- True
- False
21: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- .8
- 1.7
- 1.2
- .1
22: 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
23: 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
24: Can ammonia be used on domestic system?
- yes
- no
- no, unless there is proper ventilation system installed
- yes, for systems under 10 tons
25: 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