Topics: All categories in the pool
1: Increasing superheat will do what to your system?
- Increase liquid flow
- Nothing
- Decrease liquid flow
- Increase gas flow
2: Starting relays for a single phase compressors are used to remove the starting circuit from operation when the motor reaches approximately ____ percent of its speed.
- 75
- 100
- 24
- 50
3: What type of voltage cause a potential relay to open?
- 24 volt supply from the thermostat
- 120 volt line voltage
- Pick-up voltage
- none of the above
4: NH3 is
- R-508A
- R-718
- lithium bromide
- ammonia
5: A compressor in which the increase in vapor pressure is attained without changing the internal volume of the compression chamber is called
- negative displacement compressor
- non-positive displacement compressor
- non-volumetric displacement compressor
- neutral chamber-type compressor
6: A relief valve shall be located at least ___ above grade.
- 36'
- 15'
- 25'
- 10'
7: Heat cannot of itself, pass from a
- cold to a warmer body
- warm to a colder body
- state of hot energy to a state of cold energy
- None of the above
8: What is R-22?
- CCFCM
- HFC
- Chlorodifluoromethane
- Chlorofluoromethane
9: How much refrigerant can be stored in a mechanical room outside of the system?
- 150
- 330
- 100
- 200
10: A 120 volt motor rated at 1,800 watts. You find the motor is drawings 25 amps. The motor is
- drawing RLA and is running as it should
- drawing LRA and is seized and should be replaced.
- running hot
- none of the above
11: A 50 VA control transformer with a 25 volt control output would be rated for _________ amps.
- 1250
- 2.5
- There isn't enough information to answer.
- 2
12: A rule of thumb in air conditioning is ____ CFM per ton?
- 500
- 100
- 600
- 400
13: How are safety controls wired in a circuit?
- Either series or parallel
- Parallel
- Series/parallel
- Series
14: Low pressure systems have what kind of compressor?
- Scroll
- Centrifugal
- Rotary
- Reciprocating
15: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
- 700F
- 1000F
- 800F
- 600F
16: 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 R-11
- Flush with ammonia
- Flush with R-718
- Flush with RX-11
17: How many CFMs are required per square foot of commercial office occupied space
- 5 CFM
- 15 CFM
- .5 CFM
- 20 CFM
18: What is the purpose of a surge capacitor on a contactor?
- to keep the contactor pulled in
- to balance the sine waves
- to protect low voltage equipment
- to provide smoother start/stops
19: The rupture disc on a low-pressure chiller typically releases pressure at
- 15 psig
- 0 psig
- 10 psig
- 5 psig
20: What is the refrigerant dichlorodifluoromethane?
- R-12
- R-134A
- R-123
- R-22
21: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
22: If the spring is adjusted to increase the superheat, this new setting will
- allow more liquid into the evaporator
- have no effect on the frost line
- lengthen the frost line
- shorten the frost line
23: Adjusting the spring pressure on a TXV
- changes superheat
- changes subcooling
- adjusts the bulb charge
- makes no difference
24: Sensible heat is the heat added to a substance to
- cause evaporation
- raise its temperature
- change its state
- freeze it
25: What would be the classification of a prison?
- Place of assembly
- Industrial
- Large mercantile
- Institutional