Topics: All categories in the pool
1: How would you know if there was a loss of crankcase pressure?
- oil will thicken
- oil level will rise
- oil will foam
- oil will thin out
2: No open flames are allowed in the machinery room unless?
- Approved by the installing contractor
- Approved by the authorized person
- Never can be allowed
- Only when combustion air is provided from outside of the machinery room
3: What is considered a cooling agent?
- any liquid used for the transmission of heat when vaporization occurs
- any liquid used for the transmission of heat when condensation occur
- any liquid used for the transmission of heat without vaporization
- any liquid used for the transmission of heat without condensation
4: Which refrigerant class listed below is the most flammable?
- A-1
- B-2
- A-3
- C-3
5: Refrigeration devices shall be equipped with a ____ to protect against unexpected pressure due to a malfunction or fire?
- Relief valve
- Temperature limiter device
- T&P device
- Circuit Breaker
6: R-410A can segregate in the system or chemically change its composition due to a leak.
- True
- False
7: Each machinery room shall contain
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
- high and low pressure controls
8: What is absolute humidity?
- the amount of moisture in the air per one pound of 50% RH air
- the amount of moisture in the air in grains of cubic feet of volume
- the amount of moisture in the air in grains of square feet of volume
- none of the above
9: An accumulator can be located between the
- condenser and evaporator
- first stage and second stage compressors
- evaporator and compressor
- compressor and condenser
10: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 125 psig
- 327 psig
- 255 psig
- 365 psig
11: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to
- liquid line that is too small
- shortage of refrigerant
- liquid line that had too high vertical lift
- All of the above
12: When the compressor is below the condensor
- traps are needed on the discharge line
- traps are needed on the suction line
- traps are needed on the oil return line
- traps are not needed on this type of system
13: Where are the three places that the discharge from an ammonia relief valve be piped?
- atmosphere, tank containing water, where the A.H.J. indicates
- underground, into drain, into mechanical room
- to chemical neutralizing tank only
- none of the above
14: On cooling towers, what causes the condenser water to drop
- tower fans
- ambient temperatures
- sensible heat
- evaporation of the water droplets
15: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
16: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?
- 10 amps
- 20 amps
- 5 amps
- 15 amps
17: Gauge pressure is
- force of pressure above that of atmospheric
- absolute pressure
- atmospheric pressure
- what a gauge reads when checking pressures on a chilled water system.
18: Control systems can be classified by
- economy of operation
- tonnage of system
- source of power
- safety
19: Three-phase motors have what type of windings?
- three run windings
- three start windings
- one start winding and one run winding.
- three run windings and 3 start windings
20: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
- 240v
- 277v
- 120v
- 208v
21: If a purge unit fails on a low pressure chiller, what are the symptoms?
- low pressure chillers do not have purge units
- high head pressure
- increased capacity
- low suction pressure
22: "P" represents ______ in the Watt's law formula
- reactance
- amperage
- watts
- voltage
23: One ton of refrigeration is defined as ______ btu/minute.
- 12,000
- 200
- 60
- 720,000
24: How are a compressor and condenser fan wired?
- series
- parallel
- series-parallel
- parallel-series
25: Pressure vessels of 10 cubic feet or more gross volume shall use
- at least one rupture member
- a dual pressure-relief valve if charging into the atmosphere
- at least three means of discharge and/or rupture discs
- both a and b are correct