Topics: All categories in the pool
1: In a horizontal shell & tube condenser, the ammonia is liquefied by
- removing the latent heat of fusion
- removing the latent heat of vaporization
- passing thru the tubes from top to bottom
- water sprayed over condenser
2: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 330 lbs
- 55 lbs
- 660 lbs
- 500 lbs
3: How many gallons of water do you need per pound of ammonia?
- 1
- 50
- 10
- 100
4: When an A/C system is excessively low on refrigerant
- it can become contaminated with water
- there can be nuisance trip outs
- the suction line may be too hot to touch
- All of the above
5: What was the main reason for enacting the no venting rule of July 1, 1992?
- Ozone depletion
- Green house effect
- Global warming potential
- All of the above
6: What is a megaohm meter?
- An electric meter used by electricians to test large 3-phase blower motors for the correct rotation
- An electric meter that measures very high resistance values by sending a low voltage AC signal into the object being tested
- Is an electric meter that measures extremely low resistance valves by sending high DC voltage signal into the object being tested.
- An electric meter that measures very high resistance values by sending a high DC voltage signal into the object being tested
7: In an A/C unit, dirty filters will cause
- low oil pressure
- high discharge pressure
- low suction pressure
- high suction pressur
8: _____ and its alloys are suitable for use with ammonia systems.
- Magnesium
- Copper
- Aluminum
- Zinc
9: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
- CO Sensing
- refrigerant sensing
- phosgene gas sening
- A group sensing
10: No open flames are allowed in the machinery room unless?
- Approved by the installing contractor
- Never can be allowed
- Approved by the authorized person
- Only when combustion air is provided from outside of the machinery room
11: The purpose of a receiver is
- a vessel to store refrigerant outside the system
- to increase the capacity that the system can hold
- to use a a later date
- all of the above
12: A premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space such as auditoriums, ballrooms, classrooms, passenger depots, restaurants, and theaters is considered a(n)
- institutional occupancy
- illegal occupancy
- commercial occupancy
- public assembly occupancy
13: Heat transferred by conduction from one body to another is done
- via solids
- via liquids
- via radiation
- via heat rays
14: Ammonia vaporization takes place at what temperature?
- -28F
- -110F
- -460F
- -32F
15: When energized, a normally open relay will be
- open
- noisy
- closed
- depends on the type and class of the relay
16: Liquid refrigerant R-22 enters an evaporator at 50.2 psig, 20F and leaves 37F, its pressure as it leaves will be
- 50.2 psig
- 66.1 psig
- 70.8 psig
- 43.3 psig
17: 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
- competent welder
- licensed technician
- licensed welder
18: Mercury was used in thermometers primarily because it
- never freezes
- vaporizes at very high temperatures
- was inexpensive
- expands uniformly
19: R-410A is classified as a ____ refrigerant on the safety matrix.
- A-1
- A-2
- B-2
- B-1
20: 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 typical refrigerant used on newer air conditioning and heat pump ssytems
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and design temperature is between -20F to 366F
21: Secondary refrigerants are usually
- water or brine
- alcohol
- Prestone anti-freeze
- expensive
22: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is
- Latent heat
- Specific heat
- Enthalpy
- Sensible heat
23: What device should be used on low-temperature freezers?
- high capacity TXV
- discharge muffler
- hot-gas by-pass
- oil separator
24: Control systems can be classified by
- safety
- source of power
- economy of operation
- tonnage of system
25: The Board of Boilers adopts by reference
- the MACS Pressure Vessel Code of Massachusetts
- the 1997 ANSI/ASHRAE Safety Code
- Montreal Protocol Safety Code
- MSCA Code