Topics: All categories in the pool
1: 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
2: Megaohm meter's main function is
- to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
- to detect very high resistances to ground of refrigeration or air conditioning compressors
- to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
- Both a and b are correct
3: Which of the following is not an air velocity meter?
- Anemotherm
- Hydrometer
- Velometer
- Anemometer
4: 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
5: All machine rooms must be outfitted with a detector that _______?
- activates an audible alarm
- activates a visual alarm
- starts the ventilation system
- All of the above
6: Class T machine room
- shall include closets used for setting equipment
- shall have refrigerant leak detecting systems installed inside and outside the room
- has no flame producing apparatus permanently installed
- shall have remote controls to stop the action of the refrigerant compressor
7: How many BTU's is produced by one watt of energy
- 1
- 3.41
- 2.57
- 3.00
8: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
- 1.5
- 1
- 1.2
- 2.2
9: What refrigerant doesn't have to be classifted?
- R-134a
- R-718
- R-717
- R-711
10: There can be no airflow from an occupied space through a machine room unless what?
- System is high velocity
- System is ducted and sealed
- Duct is not located in the ceiling
- None of the above.
11: High pressure controls should be set no higher than
- 80% of set point
- 25% of set point
- 10% of set point
- 90% of set point
12: Materials used in construction and installation materials used in the manufacture or installation of refrigerating equipment shall be suitable for conveying refrigerant and the refrigerant oils and will not deteriorate in the presence of what?
- Oil and water
- Moisture and air
- Air and dirt
- Water and soap
13: The low pressure oil safety switch
- must be reset manually
- resets itself automatically
- resets itself after the time delay has terminated
- never trips
14: When is the space above a drop ceiling calculated as space for refrigerant limit quantities?
- When it's used as part of a supply or return air system
- When there are sprinklers above
- When there is a space 6' or more above it
- When its white
15: How many different groups of refrigerants are there?
- 15
- 7
- 3
- 11
16: Group A3 refrigerants have a ______ flammability rating than Group B1 refrigerants
- there is no Group B1 refrigerants
- lower
- the same
- higher
17: What section governs pressure vessels?
- Section 8 ASHREA 15 ASME unfired
- OSHA
- Section 1 ASHREA 15 ASME fired
- Section ASHREA 34
18: At higher altitudes, the boiling point of refrigerant is
- higher
- the same
- equal to the coefficient of water at 32F
- lower
19: A pressure vessel having an inside diameter of 6” or less shall be sufficient to withstand ____times the pressure of the saturation temperature of the refrigerant or ____times the critical pressure of the refrigerant, whichever is less.
- 3.0, 3.5
- 2.5, 2.5
- 6.6, 6.6
- 2.5, 3.0
20: Which refrigerant class listed below is the most flammable?
- C3
- A2
- A3
- B2
21: A single pole-double throw switch uses how many wires?(excluding the ground)
- 4
- 2
- 5
- 3
22: A Lithium-bromide system is an absorption system that
- uses ammonia as a refrigerant and lithium bromide as an absorbent
- uses water as a refrigerant and lithium bromide as an absorbent
- uses salts as an absorbent and lithium bromide as a refrigerant
- uses water as a absorbent and lithium bromide as a refrigerant
23: Increasing superheat will do what to your system?
- Increase gas flow
- Decrease liquid flow
- Increase liquid flow
- Nothing
24: The difference between saturated liquid and saturated vapor is
- volume
- temperature
- heat
- pressure
25: Three-phase motors have what type of windings?
- one start winding and one run winding.
- three run windings and 3 start windings
- three run windings
- three start windings