Topics: All categories in the pool
1: What is the purpose of a surge capacitor on a contactor?
- to keep the contactor pulled in
- to provide smoother start/stops
- to protect low voltage equipment
- to balance the sine waves
2: _____ alloys shall not be used in contact with an halogenated refrigerants.
- Copper
- Zinc
- Magnesium
- Nickel
3: What is a Category "D" fluid?
- 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 toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily contact
- A typical refrigerant used on newer air conditioning and heat pump ssytems
- Any fluid that exceeds 150 psig and has design temperature of over 366F
4: 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
5: 1 Watt = ______ BTU's?
- 7.216
- 3.412
- 4.482
- 12
6: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
7: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 71 ohms
- 104 ohms
- 80 ohms
- 27 ohms
8: A single pole-double throw switch used how many wires excluding the ground wire?
- three
- four
- five
- two
9: Atmospheric pressure is equal to
- 29.92" Hg
- 14.7 psia
- 14.7 psig
- both a & b
10: Ammonia (NH3) is a group III refrigerant
- True
- False
11: After setting up a forward curved fan for the desired conditions, something happened to lower the total static pressure the fan had to operate against. Which would occur?
- CFM and HP decrease
- RPM and CFM increase
- CFM and RPM decrease
- CFM and HP increase
12: The density of a gas refers to
- pounds per absolute pressure
- pounds per cubic foot
- pounds per square foot
- cubic feet per pound
13: A micron is
- one millonths of a micrometer
- one millonths of a centimeter
- one thousandths of a millimeter
- a larger unit of measurement than Hg
14: The outer portion of shell of the compressor used on low-pressure chillers is called the
- baffle
- volute
- nozzle
- suction
15: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 45F
- 32F
- 155F
- 158F
16: Machinery rooms must be vented to ______?
- outdoors
- neutralizing tank
- unoccupied spaces
- basement
17: 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
18: Gauge pressure is
- Atmospheric pressure
- Force of pressure above that of atmosphere
- Barometric pressure
- Absolute pressrue
19: A High-Probability System
- is a system highly likely to leak form a failed connection or component of such system
- is such that a leak of refrigerant from a failed connection will enter an unoccupied space
- is such that a leak of refrigerant from a failed connection will enter the occupied space
- is such that any leak will cause injury or death to anyone within a 100 square foot area
20: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.
- Lithium bromide
- ammonia
- HCFC-123
- CFC-11
21: 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.
22: A hotel is considered a _______ occupancy.
- mercantile
- residential
- institutional
- commercial
23: The two basic types of evaporators are
- prime surface and finned
- flooded and direct expansion
- finned and plate
- direct expansion and plate
24: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- 2.5 times the design pressure
- the aggregate of the high side and low side
- the low side
- the high side
25: System design pressures must take into consideration, not only, pressures found during normal operation but also what?
- When it's cold out
- When there is a malfunction on the high side
- When its warm out
- All of the above