Topics: All categories in the pool
1: 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
- when ambient temperature are low
- at start-up
2: Calculate the voltage in a series circuit when the total amperage is 10 amps and the resistors have values of: R1=12 ohms, R2=8 ohms, R3=4 ohms
- 2,400 volts
- 24.0 volts
- 2.40 volts
- 240 volts
3: When is the space above a drop ceiling calculated as space for refrigerant limit quantities?
- When there is a space 6' or more above it
- When its white
- When there are sprinklers above
- When it's used as part of a supply or return air system
4: The main purpose of the accumulator is to
- store liquid refrigerant
- prevent liquid slugs at the compressor
- provide space for vapor to accumulate
- provide space for the accumulation of oil and containminants
5: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
- .9776 watts
- 9,776 watts
- 977.6 watts
- 9.776 watts
6: A hissing noise at the expansion valve is a good indication that
- gas is passing thru it
- expansion valve is oversized
- nothing is passing thru
- liquid is passing thru it
7: The solution that leaves the concentrator in an absorption chiller is referred to as the
- diluted solution
- absorbed solution
- strong solution
- weak solution
8: Horizontal piping should be run level.
- Yes, if the condenser is located above the evaporator
- True
- No, unless the supervisor on the job says so.
- False
9: Group A1 refrigerants over ____ pounds in a system must discharge to the atmosphere
- 330
- 110
- 1,000
- 6.6
10: The boiling point of a refrigerant is based on
- Temperature
- Heat content
- a pressure-temperature relationship
- None of the above.
11: Booster compressors, pump refrigerant into the
- heat & plate heat exchanges
- receiver
- high side of the secondary compressor
- low side of the primary compressor
12: A high side float is a
- float type valve that controls the amount of refrigerant stored in the receiver
- metering device used on critically charged systems that controls the level of the liquid refrigerant in the high pressure side of the system.
- float type switch that stops the compressor when the pressure on the high side becomes too high
- float type valve that controls the crankcase oil level
13: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 50
- 22
- 66
- 25
14: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.
15: What type of voltage causes the winding in a potential relay to open?
- BEMF (Back Electro-Motive Force)
- 24V control voltage from the thermostat
- 120V line voltage
- None of the above
16: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- critical pressure
- design pressure
- low pressure
17: All low-pressure chillers use which type of compressor?
- Reciprocating
- Rotary
- Centrifugal
- Scroll
18: A direct system
- is one which encloses a separate body of evaporative refrigerant
- is a self-contained complete factory made and tested system
- is where the refrigerant comes in contact with the space refrigerated
- is on where brine is cooled & circulated to the space refrigerated
19: What refrigerant doesn't have to be classified?
- R-718
- R-134A
- R-422A
- R-717
20: Gauge pressure is
- what a gauge reads when checking pressures on a chilled water system.
- absolute pressure
- force of pressure above that of atmospheric
- atmospheric pressure
21: On a single phase motor, when does the start winding cut out?
- At 75% of its full rated speed
- Start windings do no cut-out of the run cycle
- At 50% of its full rated speed
- At 25% of its full rated speed
22: A Low-Probability System
- is such that a leak of refrigerant from a failed connection will enter the occupied space
- is such that a leak of refrigerant from a failed connection can not enter the occupied space
- is a system highly likely to leak form a failed connection or component of such system
- is such that any leak will cause injury or death to anyone within a 100 square foot area
23: A run capacitor is wired in series with the _____ windings.
- start capacitor
- start
- common
- run
24: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- Low head pressure and high suction pressure
- High head pressure and low suction pressure
- Low suction pressure and low discharge pressure
- High suction pressure and high discharge pressure.
25: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b