Topics: All categories in the pool
1: What is the purpose of a surge capacitor on a contactor?
- to protect low voltage equipment
- to keep the contactor pulled in
- to balance the sine waves
- to provide smoother start/stops
2: A EPR valve is installed on what type of evaporators?
- plate evaporators
- high-temperature evaporators
- shell and tube evaporators
- low-temperature evaporators
3: No open flames are allowed in the machinery room unless?
- Only when combustion air is provided from outside of the machinery room
- Approved by the installing contractor
- Approved by the authorized person
- Never can be allowed
4: What is considered a cooling agent?
- any liquid used for the transmission of heat when condensation occur
- any liquid used for the transmission of heat without condensation
- any liquid used for the transmission of heat without vaporization
- any liquid used for the transmission of heat when vaporization occurs
5: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- fusion plug
- fusible plug
- relief plug
- rupture plug
6: What happens to copper joints when overheated?
- nothing
- joint becomes oxidized and ditorted
- copper becomes harder
- none of the above
7: Ashrae states that the equipment on a building needs to conform to adjacent buildings classifications when within ____ feet from opening and intakes.
- 20
- 15
- 50
- 75
8: What refrigerant doesn't have to be classifted?
- R-711
- R-718
- R-717
- R-134a
9: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- centrifugal switch
- duel-voltage switch
- printed circuit board (PCB)
- motor starter
10: A start capacitor in series with a start winding will
- increase starting torque
- decrease the amp draw of the motor
- increase running efficiency
- increase the amp draw of the motor
11: What is used to check very low air pressures in air conditioning duct?
- Barometer
- Vacuum gauge
- Anemomter
- Manometer
12: Give an example of a secondary coolant?
- R-717
- R-410A
- R-718
- R-12
13: A rule of thumb in air conditioning is ____ CFM per ton?
- 500
- 100
- 400
- 600
14: How are safety controls wired in a circuit?
- Series
- Parallel
- Series/parallel
- Either series or parallel
15: A restaurant is classified as a
- mixed occupancy
- commercial occupancy
- public assembly occupancy
- large mercantile occupancy
16: Total heat of a substance is considered
- specific heat
- enthalpy
- empathetical
- sensible heat
17: Which refrigerant class listed below is the most flammable?
- A3
- B2
- A2
- C3
18: Control systems can be classified by
- source of power
- safety
- economy of operation
- tonnage of system
19: What is an egress?
- A valve put on the low side of the system to prevent frosting
- A code violation
- An entrance or exit
- An escape route
20: Pressure vessels with an internal volume of 3 cubic feet or less
- shall use fusible plugs
- shall use pressure relief devices
- do not need pressure relief protection
- shall use pressure relief devices or fusible plugs
21: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- The Li-Br solution will become more diluted
- System operating pressure will drop
- The Li-Br solution will become more concentrated
- Rust can form
22: One atmosphere equals
- 0 psig
- 14.7
- 29.4
- 0 psia
23: A water regulating valve opens when
- the compressor is on
- when the power is on
- the head pressure rises
- when the power is on there is an overcharge of refrigerant
24: The 4 basic methods of determining whether the proper amount of refrigerant is being introduced into the system are
- sight glass, weight, pressure, and dipstick
- sight glass, weight, paper method, and frost line.
- sight glass, weight, pressure, and frost line
- Buss-eye, weight, pressure, and frost line
25: _____ alloys shall not be used in contact with an halogenated refrigerants.
- Magnesium
- Zinc
- Copper
- Nickel