Topics: All categories in the pool
1: The first step in mechanical refrigeration is
- compression
- expansion
- evaporation
- condensation
2: Which refrigerant(s) is an HFC?
- R-22
- R-410A
- R-502
- All of the above
3: One watt of electrical energy in a resistive heater will provide _____ BTU/hr
- 34.15
- 6.830
- 16.64
- 3.415
4: A pressure relief should be located at least _______ from windows and doors.
- 20'
- 30'
- 25'
- 15'
5: What is the maximum voltage range allowed on an electrical circuit?
- 20%
- 15%
- 5%
- 10%
6: What does safe access mean?
- Well-lit exit signs
- OSHA approved
- A clear unobstructed path to the equipment and controls
- Locked doors
7: R-12. R-22, and R-40 are considered Group I refrigerants.
- True
- False
8: On a centrifugal compressor, stationary diffuser vanes are needed to
- prevent high pressure on the packing
- increase the clearance space
- convert velocity energy to pressure
- stop gas flow
9: Pressure is the equivalent of
- area times force
- force per unit area
- force
- force times area
10: Most CFC's are
- inert
- inert but toxic
- toxic
- flammable
11: Which occupancy can ammonia be used in?
- commercial
- depends on the quantity of freon
- redifential
- industrial
12: It takes how many BTU/hr to melt one pound of ice at 32F
- 212
- 144
- 970
- 180
13: 14.7 psia is equivalent to
- atmospheric pressure at seal level
- 29.92" Hg
- 0 psig
- All of the above.
14: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
- low side of the system
- the liquid side of the system
- the vapor side of the system
- high side of the system
15: When this is installed on the high side of a system, it must be capable of reading 1.2 times the design pressure (ASHRAE 15 9.11.3)
- Pressure gauge
- Temperature gauge
- Sight glass gauge
- All of the above
16: Liquid level gauge glasses shall have automatic closing shut off valves, except Bull's eye or reflex type.
- True
- False
17: A High-Probablity system
- is a system highly likely to leak from a failed connection or component of such system
- is such that a leak of refrigerant from failed connections will enter the occupied space
- is such that a leak of refrigerant from failed connections will enter the unoccupied space
- is such that any leak will cause injury or death to anyone within a 100 square foot area
18: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- low pressure
- design pressure
- high pressure
- critical pressure
19: Volts x amps equals
- Ohms Law
- Watts
- Inductance
- Impedance
20: What is Trichlorotrifluoromethane?
- R-12
- R-113
- R-13
- R-11
21: Foaming of oil in a compressor is most likely to occur
- at start-up
- when the evaporator temperatures are below 32F
- when there is insufficient air across the condenser(i.e., dirty coil)
- when ambient temperature are low
22: The best way to determine the voltage requirement for an electrical component is to
- determine the capacity of the service panel
- check with the utility company
- read the voltage with a mulitmeter
- read the nameplate data
23: Booster compressors connect to the ____ side of the compressor
- low side
- oil side
- vapor
- liquid
24: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- fusion plug
- relief plug
- fusible plug
- rupture plug
25: Excessive head pressure is often caused by
- air cooled condenser is plugged
- leaking reed valve on the discharge side
- insufficient refrigerant
- thermostat set too high