Topics: All categories in the pool
1: When a receiver is greater than 3 cubic feet but less than 10 cubic feed, what is the minimum relief device required?
- fusible plug
- relief valve
- rupture disc
- all of the above
2: The discharge relief valve is located (9.4.6)
- between the compressor and oil separator
- between the compressor and reciever
- on top of the condensor
- between the compressor and the stop valve
3: Can you use Ammonia in industrial applications?
- Yes, always
- Yes, Under certain condidtions
- No, never
- When mixed with R-718
4: 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
5: Group A3 refrigerants have a ______ flammability rating than Group B1 refrigerants
- the same
- lower
- higher
- there is no Group B1 refrigerants
6: Low-side system leaks in a low-pressure chiller will often result in
- air being pulled into the system
- water being pulled into the system
- nitrogen leaking out of the system.
- system refrigerant leaking from the system
7: What measures gas pressure?
- Hygrometer
- Barometer
- Manometer
- Hydrometer
8: Heat transferred by conduction from one body to another is done
- via solids
- via radiation
- via heat rays
- via liquids
9: What refrigerant doesn't have to be classifted?
- R-134a
- R-718
- R-717
- R-711
10: Atmospheric pressure is equal to
- 29.92" Hg
- 14.7 psia
- 14.7 psig
- both a & b
11: A chiller entering and leaving temperature difference is?
- 50 degrees F
- 10 degrees F
- 20 degrees F
- 5 degrees F
12: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is
- Sensible heat
- Specific heat
- Latent heat
- Enthalpy
13: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
14: Clearance volume
- is the same on all compressors
- has no effect on compressor capacity
- varies depending on compressor speed
- affects compressor capacity
15: Sensible heat is the heat added to a substance to
- raise its temperature
- freeze it
- cause evaporation
- change its state
16: The principle used in continuous type absorption systems is
- Charles's Law
- Boyle's Law
- Ohm's Law
- Dalton's Law
17: When a refrigerating machinery room is used, the emergency procedures shall be posted
- on a conspicuous card located near the evaporator
- outside the room, immediately adjacent to each door
- on a conspicuous card located near the compressor
- inside the room, immediately adjacent to each door
18: On an air cooled condenser, if the ambient air is 35F and dropping, what's its effect to the condensor?
- it would make the condenser more efficient
- it would make the condenser less efficient
- it would have no effect on the condenser
- it would cause the condenser to sweat
19: What type of voltage cause a potential relay to open?
- 24 volt supply from the thermostat
- 120 volt line voltage
- Pick-up voltage
- none of the above
20: one BTU equals
- 12,000 hp
- 31.4 hp
- 3.41 hp
- Pi
21: The most common type of motor starter is
- across the line starter
- part winding starter
- duel-winding starter
- delts-wye starter
22: Which refrigerant(s) is an HFC?
- R-22
- R-410A
- R-502
- All of the above
23: How far from the window does a relief valve need to be according to ASHRAE-15?
- At least 20'
- At least 40'
- There is no minimum for relief valve and windows.
- At least 30'
24: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- starved evaporator
- compressor suction valve stuck open
- too small evaporator
- overcharged
25: Lithium-bromide, Li-Br, is best characterized as a
- salt
- soil
- sugar
- sand