Topics: All categories in the pool
1: What is a Category "D" fluid?
- Any fluid that exceeds 150 psig and has design temperature of over 366F
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily contact
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and design temperature is between -20F to 366F
- A typical refrigerant used on newer air conditioning and heat pump ssytems
2: When systems are protected by a high pressure relief device, the compressor's pressure limiting device shall be set at or below ____ % of the operating pressure of the high side relief device.
- 100
- 80
- 90
- 110
3: If the spring is adjusted to increase the superheat, this new setting will
- have no effect on the frost line
- allow more liquid into the evaporator
- shorten the frost line
- lengthen the frost line
4: The first step in mechanical refrigeration is
- evaporation
- condensation
- compression
- expansion
5: Pressure vessels with an internal volume of 10 cubic feet or more
- shall use pressure relief devices
- shall use rupture discs or duel pressure relief valves
- shall use fusible plugs
- shall use pressure relief devices or fusible plugs
6: The main purpose of the accumulator is to
- provide space for the accumulation of oil and containminants
- provide space for vapor to accumulate
- prevent liquid slugs at the compressor
- store liquid refrigerant
7: Which refrigerant is lighter than air?
- R-11
- R-134a
- R-717
- R-123
8: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
- refrigerant sensing
- A group sensing
- phosgene gas sening
- CO Sensing
9: Liquid line filter-driers on a 410A system must be rated for no less than
- 600 psig
- 200 psig
- 400 psig
- 1000 psig
10: 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
11: How many refrigerant classifications are there for toxicity?
- 1
- 3
- 5
- 2
12: A declaration test is needed when the system contains more than
- 55 lbs
- 120 lbs
- 65 lbs
- 110 lbs
13: Class A refrigerants are considered
- non-toxic
- flammable
- non-flammable
- toxic
14: A check valve is a device
- designed to allow the flow of refrigerant gas in both directions
- that is always spring loaded
- with a pressure drop
- found on high pressure steam systems
15: Liquid refrigerant R-22 enters an evaporator at 50.2 psig, 20F and leaves 37F, its pressure as it leaves will be
- 66.1 psig
- 43.3 psig
- 50.2 psig
- 70.8 psig
16: 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?
- Water and soap
- Moisture and air
- Air and dirt
- Oil and water
17: What does an anemometer measure?
- temperature
- velocity
- voltage
- amperage
18: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
- EEV
- Solenoid valve
- EPR valve
- CPR valve
19: Control systems can be classified by
- tonnage of system
- economy of operation
- source of power
- safety
20: Pressure vessel having an inside diameter exceeding 6” with an internal pressure greater than 15psig shall be marked directly on or on the nameplate the letters _______________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- “UL”
- “UM” and “UV”
- “U” or “UM”
- “UV”
21: Which oil is hydoscopic?
- animal
- mineral
- SW30
- polyolester
22: The rupture disc on a low-pressure chiller typically releases pressure at
- 0 psig
- 15 psig
- 5 psig
- 10 psig
23: The location of the thermal bulb for the TXV on the evaporator effects
- both the pressure and temperature in the feeler bulb
- the amount of superheat required to operate the TXV
- the amount of liquid in the evaporator
- the amount of gas in the evaporator
24: A start capacitor is wired in _____ with the start windings.
- series-parallel
- junction
- series
- parallel
25: What type of copper is not permitted on refrigeration systems?
- Type L
- Type N
- Type K
- Type M