Topics: All categories in the pool
1: An accumulator can be located between the
- condenser and evaporator
- compressor and condenser
- first stage and second stage compressors
- evaporator and compressor
2: Ammonia is under what safety classification?
- A3
- B2
- B3
- B1
3: How many BTU's is produced by one watt of energy
- 1
- 3.41
- 3.00
- 2.57
4: How far from the ground does a relief valve need to be?
- Not more than 3' above grade
- At least 20' above grade
- At least 25' above grade
- At least 15' above grade
5: How many opening forces operate a thermostatic expansion valve?
- 3
- 4
- 2
- 1
6: On cooling towers, what causes the condenser water to drop
- evaporation of the water droplets
- ambient temperatures
- sensible heat
- tower fans
7: 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
- 5 amps
- 15 amps
- 20 amps
8: The solution that leaves the concentrator in an absorption chiller is referred to as the
- strong solution
- diluted solution
- weak solution
- absorbed solution
9: "R" represents ___ in the Ohm's law formula
- resistance
- amperage
- capacitance
- voltage
10: Pipe identification labels are required when the system contains more than
- 110 lbs
- 65 lbs
- 120 lbs
- 55 lbs
11: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
- 29F
- 21F
- 11F
- 9F
12: A rule of thumb in air conditioning is ____ CFM per ton?
- 600
- 100
- 400
- 500
13: R22 and 410A operate at the same range of condensing and evaporating temperatures
- true
- false
14: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
15: All welding done on any refrigeration system or piping covered by 522 CMR 9.00 shall be performed by a according to Section IX of the ASME code
- competent welder
- welder qualified
- licensed welder
- licensed technician
16: When is the space above a drop ceiling calculated as space for refrigerant limit quantities?
- When there are sprinklers above
- When its white
- When it's used as part of a supply or return air system
- When there is a space 6' or more above it
17: Before replacing a seized compressor, the _______ should be determinded.
- type of refrigerant
- current draw
- cause of seizure
- designed head pressure
18: Emergency shutdown procedures, including precautions to be observed in case of a breakdown or leak over 55 lbs of refrigerant charge, shall be displayed on a conspicuous card located as near as possible to the
- boiler
- compressor
- evaporator
- outside the machinery room
19: A single pole-double throw switch used how many wires excluding the ground wire?
- three
- four
- five
- two
20: How are safety controls wired in a circuit?
- Either series or parallel
- Series
- Parallel
- Series/parallel
21: Refrigerants shall be classified by
- toxicity and flammability
- maximum permissible quantities of each group
- requirements for commercial, industrial, and residential occupancies
- color codes
22: Which refrigerant class listed below is the most flammable?
- B2
- A3
- C3
- A2
23: Halogen refrigerants are corrosive to which type of metal?
- black iron
- magnesium
- copper
- stainless steel
24: In a system designed for sub-zero ambient temperatures, what must be added?
- Nitrogen
- Booster compressor
- Low-ambient kit
- Infrared dye for leak identification
25: Absolute pressure is
- Gauge Pressure
- Atmospheric Pressure
- Gauge + Atmospheric Pressure + Pi
- none of the above