Topics: All categories in the pool
1: The purpose of an accumulator is to
- store excess refrigerant from the reciver
- assure no liquid returns to the compressor
- reduce friction loss to the flow of refrigerant
- filter out impurities from the system
2: Which of the following are considered inorganic refrigerants?
- R-717 and R-718
- 410A and R-407C
- R-500 and R-502
- None of the above
3: "I" represents ____ in the Ohm's law formula.
- voltage.
- amperage
- capacitance
- resistance
4: What is the maximum voltage range allowed on an electrical circuit?
- 15%
- 10%
- 20%
- 5%
5: Which occupancy can ammonia be used in?
- redifential
- industrial
- depends on the quantity of freon
- commercial
6: Large Mercantile occupancy is a premise or that portion of a premise where more than ____ persons congregate on levels above or below the street level to purchase personal merchandise.
- 350
- 400
- 100
- 250
7: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- overcharged
- too small evaporator
- starved evaporator
- compressor suction valve stuck open
8: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 660 lbs
- 330 lbs.
- 55 lbs
- 550 lbs
9: 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
10: A normal operating evaporator temperature of R-22 for air conditioning is typically
- 55F
- 32F
- 58F
- 45F
11: The Board of Boilers adopts by reference
- Montreal Protocol Safety Code
- the 1997 ANSI/ASHRAE Safety Code
- MSCA Code
- the MACS Pressure Vessel Code of Massachusetts
12: By using nitrogen within a pipe during brazing operation,
- The explosion hazard is confined
- Copper oxide formation is prevented
- Discoloration is prevented
- Exterior scale formation is minimized
13: Which is considered the more efficient condenser?
- water cooled
- air cooled
- fan cooled
- spray cooled
14: No open flames are allowed in the machinery room unless?
- Never can be allowed
- Only when combustion air is provided from outside of the machinery room
- Approved by the installing contractor
- Approved by the authorized person
15: At higher altitudes, the boiling point of refrigerant is
- the same
- lower
- higher
- equal to the coefficient of water at 32F
16: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
17: Liquid shall not occupy more than ____ of the volume when the temperature of the refrigerant is 90F.
- 75%
- 100%
- 80%
- 90%
18: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
- moisture in the system
- oil in evaporator
- not enough oil in the system
- low head pressure
19: What is considered a cooling agent?
- any liquid used for the transmission of heat without vaporization
- any liquid used for the transmission of heat without condensation
- any liquid used for the transmission of heat when vaporization occurs
- any liquid used for the transmission of heat when condensation occur
20: What is absolute humidity?
- the amount of moisture in the air per one pound of 50% RH air
- the amount of moisture in the air in grains of cubic feet of volume
- the amount of moisture in the air in grains of square feet of volume
- none of the above
21: A hissing noise at the expansion valve is a good indication that
- nothing is passing thru
- liquid is passing thru it
- expansion valve is oversized
- gas is passing thru it
22: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- the aggregate of the high side and low side
- the low side
- 2.5 times the design pressure
- the high side
23: The first step in mechanical refrigeration is
- evaporation
- compression
- condensation
- expansion
24: Refrigerant restricted in 2004 but used for transition for decades:
- R-123
- R-22
- R-134A
- R-11
25: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?
- Foot valve
- Moisture indicator
- Stop valve
- Muffler