Topics: All categories in the pool
1: When a refrigeration or air conditioning system is installed
- a field inspection shall be made before it is put into service
- the form of certificate shall be authorized by the Department of Pubic safety
- it shall be approved by the owner for proper operation.
- it shall not be operated below prescribed pressures
2: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- Rust can form
- The Li-Br solution will become more concentrated
- The Li-Br solution will become more diluted
- System operating pressure will drop
3: The generator shell contains the
- condenser and the generator
- condenser and the absorber
- condenser, the evaporator, and the generator
- evaporator and the absorber
4: A single pole-double throw switch uses how many wires?(excluding the ground)
- 3
- 4
- 5
- 2
5: How far from the window does a relief valve need to be according to ASHRAE-15?
- At least 40'
- At least 20'
- At least 30'
- There is no minimum for relief valve and windows.
6: How many gallons of water do you need per pound of ammonia?
- 10
- 50
- 100
- 1
7: Doors communicating with outside from a mechanical room must be?
- Steel, approved, weather-stripped
- Self-closing, approved, fire door
- Self-closing, wooden, fire door
- Self-closing, aligned, fire door
8: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Rotating vanes
- Suction and discharge valves
- Nesting scrolls
- Fan-like action
9: What must be done if refrigeration lines pass through a concrete floor?
- installed through a pipe casing
- moisture barrier
- insulated
- leak checked
10: When is the space above a drop ceiling calculated as space for refrigerant limit quantities?
- When it's used as part of a supply or return air system
- When its white
- When there are sprinklers above
- When there is a space 6' or more above it
11: By using nitrogen within a pipe during brazing operation,
- Discoloration is prevented
- The explosion hazard is confined
- Exterior scale formation is minimized
- Copper oxide formation is prevented
12: The solution that is pumped into the concentrator in an absorption chiller is referred to as the
- concentrated solution
- absorbed solution
- strong solution
- weak solution
13: Ohm's Law indicates Amps X Resistance = ___________.
- Current
- Impedance
- Ohms
- Volts
14: If the power element of an expansion valve should lose its charge the valve would
- go open
- go closed
- overfeed the evaporator
- underfeed the evaporator
15: A machine room with a refrigerant system using ammonia shall
- be provided with a continuously operated ventilation system
- be considered a non-hazardous location in accordance with National Electrical code
- have no flame producing apparatus permanently installed and operated
- All of the above
16: 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 evaporator
- on a conspicuous card located near the compressor
- inside the room, immediately adjacent to each door
17: Instead of using a compressor, an absorption air-conditioning chiller uses which of the following as its driving force?
- Oil
- Electricity
- Heat
- Air
18: A chiller entering and leaving temperature difference is?
- 5 degrees F
- 10 degrees F
- 20 degrees F
- 50 degrees F
19: A normal operating evaporator temperature of R-22 for air conditioning is typically
- 55F
- 32F
- 58F
- 45F
20: What is not a requirement of a class T machine room?
- tight fitting doors
- automatic ventilation
- fire hose connection to the building fire protection system
- self-closing doors
21: Can a R22 line set be reused for a 410A system and if it can be reused, what must be done to it?
- Flush with ammonia
- Flush with R-718
- Flush with RX-11
- Flush with R-11
22: A split-phase motor has a ______ winding and a ____ winding
- duel-run, duel-start
- start, common
- run, common
- run, start
23: What is the purpose of suction/discharge traps?
- to ensure proper oil return to the compressor
- to keep oil inside the evaporator for proper oil return to the compressor
- to keep oil inside of the accumulator for proper return to the compressor
- all of the above
24: Foaming of oil in a compressor is most likely to occur
- when there is insufficient air across the condenser(i.e., dirty coil)
- when the evaporator temperatures are below 32F
- at start-up
- when ambient temperature are low
25: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 80%
- 99%
- 75%
- 90%