Topics: All categories in the pool
1: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
- 2.2
- 1.5
- 1.2
- 1
2: How are refrigerant blends classified?
- Based on best case Fractionation
- Based on worst case fractionation
- Based on the oil used
- Blends don't have to be classified
3: How much clearance do you need around the perimeter of electrical panels?
- 36"
- 12"
- 18"
- 24"
4: In a motor, an internal overload might open if
- there's an open start winding
- there's an excess current draw through the motor
- there was a high pressure refrigerant was used for a low pressure system.
- there's a direct short
5: Which of the following controllers would you expect to be most sensitive to temperature changes?
- low voltage t-stat
- aquastat
- immersion controller
- line voltage t-stat
6: How many groups of refrigerants are there?
- 3
- 5
- 7
- 1
7: When an A/C system is excessively low on refrigerant
- it can become contaminated with water
- there can be nuisance trip outs
- the suction line may be too hot to touch
- All of the above
8: What refrigerant has zero ozone depletion
- HFC
- CFC
- HCFC
- None of the above
9: What type of oil is used in R-410A systems?
- mineral oil
- naphthene
- polyalkylene glycol (PAG)
- polyolester (POE)
10: One watt of electrical energy in a resistive heater will provide _____ BTU/hr
- 16.64
- 34.15
- 3.415
- 6.830
11: Which of the following is a drop-in for R-22
- R-410A
- R-134A
- R407C
- None of the above
12: Name three things that must be done when changing refrigeration lubricant?
- Place sign, check for leaks, insulate
- You can't change lubricants.
- Make sure it's compatible, notify owner, notify AHJ
- Nothing must be done
13: "I" represents ____ in the Ohm's law formula.
- capacitance
- amperage
- resistance
- voltage.
14: "R" represents ___ in the Ohm's law formula
- resistance
- capacitance
- amperage
- voltage
15: A declaration test is needed when the system contains more than
- 110 lbs
- 55 lbs
- 65 lbs
- 120 lbs
16: Can ammonia be used on domestic system?
- no
- yes
- no, unless there is proper ventilation system installed
- yes, for systems under 10 tons
17: The leaving chilled water set point for comfort cooling is typically?
- 60
- 38
- 45
- 66
18: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 330 lbs.
- 550 lbs
- 660 lbs
- 55 lbs
19: A motor is rated for 120 volts and has a RLA (rated-load amps) of 5 amps. What is the wattage of the motor?
- 5KW
- 746 watts
- 600 watts
- 1000 watts
20: When can recovered refrigerants be reused?
- They can't
- Only when used in original owner's equipment
- Only if used in 30 days of recovery
- None of the above
21: Secondary refrigerants are usually
- expensive
- alcohol
- water or brine
- Prestone anti-freeze
22: When using nitrogen for brazing, the pressure should be:
- Very low
- 50-100 psig
- 125 psig
- Slightly below atmospheric
23: A positive displacement compressor is
- is a reciprocating type compressor with 2 or more pistons
- a compressor in which the increase in pressure is attained by changing the internal pressure of the compression chamber
- where the compressor's suction pressure and the compressor;s discharge pressure is more than 50 PSI
- a compressor in which the increase in pressure is attained by changing the internal volume of the compression chamber
24: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
- refrigerant sensing
- A group sensing
- CO Sensing
- phosgene gas sening
25: Refrigerant restricted in 2004 but used for transition for decades:
- R-123
- R-22
- R-134A
- R-11