Topics: All categories in the pool
1: On a large centrifugal system, what meters the flow to the evaporator?
- Cap tube.
- Low side float
- TXV
- High side float
2: What is the minimum size of the discharge pipe?
- Same size as the outlet of the relief valve
- One pipe size larger that the inlet of the relief valve
- Depends on size of manifold
- All of the above
3: How many different groups of refrigerants are there?
- 15
- 7
- 3
- 11
4: How many square inches per square foot?
- 64
- 144
- 98
- 24
5: The main purpose of a refrigerant detector in a machinery room is to
- inform there is a refrigerant leak int he system
- detect toxins in the air caused by a refrigerant leak
- to set off an alarm when there is refrigerant present inside the room
- all of the above
6: Oils, classified as to source, are
- naphthalene, mixed, and paraffin
- animal, vegetable, and castor
- animal, vegetable, and mineral
- naphthalene, paraffin, and castor
7: The 4 basic methods of determining whether the proper amount of refrigerant is being introduced into the system are
- sight glass, weight, paper method, and frost line.
- sight glass, weight, pressure, and frost line
- sight glass, weight, pressure, and dipstick
- Buss-eye, weight, pressure, and frost line
8: When must refrigeration system covered by the code be inspected?
- Annually
- Upon installation
- Not required
- Annually and when installed
9: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Wet bulb temperature
- Saturated temperature
- Dry bulb temperature
- Critical temperature
10: 746 watts is equal to
- 1 hp
- Pi
- 100 hp
- 10 hp
11: "R" represents ___ in the Ohm's law formula
- resistance
- voltage
- capacitance
- amperage
12: The reversing valve is commonly used
- on all heat pumps
- on multiple compressor systems
- on commercial system that involve two different temperatures
- when the code requires a check valve
13: Liquid level gauges shall have _____________ with one exception being that of the liquid level gauge bull’s eye type.
- color-coded glass to determine type of refrigerant
- moisture indicators
- automatic closing shut-off valves
- All of the above
14: Doors communicating with outside from a mechanical room must be?
- Self-closing, approved, fire door
- Steel, approved, weather-stripped
- Self-closing, wooden, fire door
- Self-closing, aligned, fire door
15: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- .1
- 1.7
- .8
- 1.2
16: Where a refrigeration or air conditioning system is installed,
- A field inspection shall be made before it is put into service
- the form or certificate shall be authorized by the Department of Public Safety
- it shall not be operated below prescribed pressuers
- The company who installed the system must notify the fire department in the jurisdiction where installed
17: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 66
- 50
- 25
- 22
18: Halogenated refrigerants cannot be used with what material?
- Stainless steel
- Magnesium alloy
- Copper
- Aluminum
19: 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
20: R-22 is classified as a ____ refrigerant on the safety matrix.
- A-2
- B-2
- B-1
- A-1
21: Which of the following is not an air velocity meter?
- Velometer
- Hydrometer
- Anemometer
- Anemotherm
22: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 155F
- 32F
- 45F
- 158F
23: By using nitrogen within a pipe during brazing operation,
- Discoloration is prevented
- Copper oxide formation is prevented
- Exterior scale formation is minimized
- The explosion hazard is confined
24: What chemical in the refrigerant set off the leak detection alarm?
- Fluorine
- Chlorine
- Both A and B
- none of the above
25: Machinery rooms shall be vented to _____________ and utilizing mechanical ventilation.
- the outdoors
- the mechanical room housing the refrigeration system
- Machinery rooms need not be vented
- the return air ducted system