Topics: All categories in the pool
1: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- overcharged
- too small evaporator
- compressor suction valve stuck open
- starved evaporator
2: The evaporator is a device to
- store liquid refrigerant
- remove heat from the refrigeration system
- Keep the compressor busy
- absorb heat into the refrigeration system
3: A water regulating valve opens when
- the compressor is on
- when the power is on there is an overcharge of refrigerant
- the head pressure rises
- when the power is on
4: How do you find net oil pressure on a compressor?
- discharge pressure - suction pressure
- gross oil pressure - suction pressure
- gross oil pressure - discharge pressure
- all of the above
5: An azeotropic refrigerant is
- a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
- a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
- a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
- none of the above
6: What is used to check very low air pressures in air conditioning duct?
- Manometer
- Vacuum gauge
- Anemomter
- Barometer
7: How much clearance do you need around the perimeter of electrical panels?
- 18"
- 12"
- 36"
- 24"
8: 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
9: What is used to check very low pressure?
- Manometer
- Hydrometer
- Hygrometer
- Velometer
10: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
- Positive displacement
- Non-positive displacement
- Low Pressure displacement
- Pressure induced displacement.
11: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- The Li-Br solution will become more diluted
- System operating pressure will drop
- Rust can form
- The Li-Br solution will become more concentrated
12: The reversing valve is commonly used
- on all heat pumps
- on multiple compressor systems
- when the code requires a check valve
- on commercial system that involve two different temperatures
13: 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
- welder qualified
- licensed technician
- competent welder
- licensed welder
14: Brazed joints melt at temperatures above
- 1,000F
- 500F
- 800F
- 1,200F
15: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 80 ohms
- 27 ohms
- 71 ohms
- 104 ohms
16: What chemical in the refrigerant set off the leak detection alarm?
- Fluorine
- Chlorine
- Both A and B
- none of the above
17: Which is considered the more efficient condenser?
- spray cooled
- water cooled
- fan cooled
- air cooled
18: A declaration test is needed when the system contains more than
- 110 lbs
- 55 lbs
- 120 lbs
- 65 lbs
19: Three-phase motors have what type of windings?
- three run windings
- three run windings and 3 start windings
- three start windings
- one start winding and one run winding.
20: If a halide torch is used for leak detection, what color is the flame if it detects a leak?
- red
- orange
- blue
- green
21: Who is permitted to access a refrigeration machine room?
- Contractors only
- Any employee
- Anyone, it's a completely safe area
- Authorized persons only
22: The instrument used to measure the specific gravity of absorption chiller solutions is the
- anemometer
- hydrometer
- Psychrometer
- refractometer
23: Excessive head pressure is often caused by
- thermostat set too high
- air cooled condenser is plugged
- leaking reed valve on the discharge side
- insufficient refrigerant
24: A direct system
- is where the refrigerant comes in contact with the space refrigerated
- is a self-contained complete factory made and tested system
- is on where brine is cooled & circulated to the space refrigerated
- is one which encloses a separate body of evaporative refrigerant
25: 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
- Water and soap
- Air and dirt
- Moisture and air