Topics: All categories in the pool
1: A High-Probablity system
- is such that a leak of refrigerant from failed connections will enter the unoccupied space
- is such that a leak of refrigerant from failed connections will enter the occupied space
- is such that any leak will cause injury or death to anyone within a 100 square foot area
- is a system highly likely to leak from a failed connection or component of such system
2: A device used to measure small pressure differences is the
- anemometer
- phsycometirc
- pyrometer
- manometer
3: The location of a thermal bulb of a TXV affects
- subcooling
- the amount of liquid returning to the compressor
- the amount of liquid refrigerant in the evaporator
- the amount of liquid in the condenser.
4: A R-410A system running with a condensing temperature of 110F and 50F evaporator temperature will read pressures of ___ on the high side and ___ on the low side
- 257 psig, 77 psig
- 455 psig, 185 psig.
- 226 psig, 68 psig
- 365 psig, 120 psig
5: The most common type of motor starter is
- duel-winding starter
- across the line starter
- delts-wye starter
- part winding starter
6: Field Inspections of refrigeration and A/C systems in Massachusetts shall be made by
- District Engineering Inspectors
- Commissioned Inspectors
- Master licensed Technician
- both a or b
7: Liquid shall not occupy more than ____ of the volume when the temperature of the refrigerant is 90F.
- 100%
- 75%
- 90%
- 80%
8: Where must a refrigeration contractor's license number be displayed?
- Trucks, invoices, and advertising
- Uniforms, checks, and invoices.
- Trucks, license plates, and uniforms
- Truck, office, every job, and on all equipment
9: A solder joint melts at temperatures of
- 600F to 900F
- 1,200F to 1,500F
- 400F to 800F
- less than 400F
10: The reversing valve is commonly used
- on all heat pumps
- on commercial system that involve two different temperatures
- on multiple compressor systems
- when the code requires a check valve
11: A 50 VA control transformer with a 25 volt control output would be rated for _________ amps.
- There isn't enough information to answer.
- 2
- 1250
- 2.5
12: The actual expansion curve of compression follows most nearly which one of the following curves?
- Volume Temperature
- Isothermal
- Adiabatic
- Pressure Temperature
13: A professional or office building would be considered what type of occupancy?
- business
- mercantile
- commercial
- public assembly
14: RPM's of a centrifugal compressor are at approximately?
- 10,000
- 30,000
- 500
- 15,000
15: A direct system
- is a self-contained complete factory made and tested system
- is one which encloses a separate body of evaporative refrigerant
- is on where brine is cooled & circulated to the space refrigerated
- is where the refrigerant comes in contact with the space refrigerated
16: Ammonia is under what safety classification?
- B2
- B3
- A3
- B1
17: When a receiver is greater than 3 cubic feet but less than 10 cubic feed, what is the minimum relief device required?
- fusible plug
- relief valve
- rupture disc
- all of the above
18: "E" represents _____ in the Watt's law formula.
- voltage
- watts
- amperage
- reactance
19: The main purpose of the accumulator is to
- store liquid refrigerant
- provide space for the accumulation of oil and containminants
- provide space for vapor to accumulate
- prevent liquid slugs at the compressor
20: Excessive head pressure is often caused by
- leaking reed valve on the discharge side
- insufficient refrigerant
- air cooled condenser is plugged
- thermostat set too high
21: Pressure vessels with an internal volume of 3 cubic feet or more
- shall use fusible plugs
- do not need pressure relief protection
- shall use pressure relief devices
- shall use pressure relief devices or fusible plugs
22: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- 1.2
- .8
- 1.7
- .1
23: In a horizontal shell & tube condenser, the ammonia is liquefied by
- removing the latent heat of vaporization
- passing thru the tubes from top to bottom
- removing the latent heat of fusion
- water sprayed over condenser
24: A premise or that portion of a premise where people transact business, receive personal service, or purchase foods, other goods is considered a
- business occupancy
- public assembly occupancy.
- commercial occupancy
- mercantile occupancy
25: Transformers are rated in
- amps
- volts
- volt-amps
- volts-ohms