Topics: All categories in the pool
1: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
2: What must be done if refrigeration lines pass through a concrete floor?
- leak checked
- installed through a pipe casing
- moisture barrier
- insulated
3: What is potential measured in?
- Henrys
- Volts
- Ohms
- Amps
4: Refrigerant restricted in 2004 but used for transition for decades:
- R-134A
- R-123
- R-11
- R-22
5: Sensible heat is the heat added to a substance to
- freeze it
- change its state
- raise its temperature
- cause evaporation
6: A class B1 refrigerant is considered
- toxic but non-flammable
- toxic and somewhat flammable
- non-toxic but highly flammable
- non-toxic and non-flammable
7: A mercury bulb controller is not recommended for
- use where vibration is severe
- low voltage use
- line or low voltage use
- line voltage use
8: Who authorizes the form of certificate of completion of refrigeration systems that should be used?
- Supervisor or project manager in charge of the installation
- Fire Marshal
- Massachusetts Board of Boiler Rules
- Owner
9: If an oil’s floc point is too high, which of the following could occur?
- plugged expansion valve
- compressor burn out
- low head pressure
- high suction pressure
10: Secondary refrigerants are usually
- water or brine
- Prestone anti-freeze
- alcohol
- expensive
11: A hissing noise at the expansion valve is a good indication that
- liquid is passing thru it
- expansion valve is oversized
- nothing is passing thru
- gas is passing thru it
12: What was the main reason for enacting the no venting rule of July 1, 1992?
- Ozone depletion
- Green house effect
- Global warming potential
- All of the above
13: Pi equals approximately
- 746
- 3.41
- 12,000
- 3.14
14: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?
- Foot valve
- Muffler
- Moisture indicator
- Stop valve
15: What is NOT a positive displacement compressor.
- Centrifugal
- Rotary
- Scroll
- Reciprocating
16: What is R-290?
- Butane
- Drop-in replacement for R-134a
- Propane
- Methyl Chloride
17: Two systems using separate refrigerants that are superimposed upon one another is called
- indirect
- single stage
- cascade
- booster
18: Systems containing more than 110 pounds must have stop valves located at the
- compressor suction inlet
- compressor discharge outlet
- receiver inlet and outlet
- All of the above
19: A start capacitor in series with a start winding will
- increase the amp draw of the motor
- increase starting torque
- increase running efficiency
- decrease the amp draw of the motor
20: Ammonia systems use ____ pressure to adjust oil pressure
- air
- stream
- liquid
- discharge
21: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- .8
- .1
- 1.2
- 1.7
22: Direct systems using Group II refrigerants
- shall be installed per instruction of the AHJ
- shall be installed in Class T machinery rooms
- shall be allowed to be used for human comfort.
- shall not be used for air condition for human comfort
23: When a refrigerating machinery room is used, the emergency procedures shall be posted
- outside the room, immediately adjacent to each door
- on a conspicuous card located near the compressor
- inside the room, immediately adjacent to each door
- on a conspicuous card located near the evaporator
24: The density of a gas refers to
- pounds per absolute pressure
- cubic feet per pound
- pounds per square foot
- pounds per cubic foot
25: Lithium-bromide, Li-Br, is best characterized as a
- sand
- soil
- sugar
- salt