Topics: All categories in the pool
1: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?
- Stop valve
- Muffler
- Foot valve
- Moisture indicator
2: Where must a refrigeration contractor's license number be displayed?
- Trucks, license plates, and uniforms
- Trucks, invoices, and advertising
- Truck, office, every job, and on all equipment
- Uniforms, checks, and invoices.
3: Doors communicating with outside from a mechanical room must be?
- Self-closing, aligned, fire door
- Self-closing, wooden, fire door
- Self-closing, approved, fire door
- Steel, approved, weather-stripped
4: When is the only time you can leave a service container attached to a system?
- Leaking system
- Recovery
- Charging
- Both b and c
5: What is the voltage of each leg to ground of a three-phase motor with a 460v supply voltage?
- 277v
- 208v
- 240v
- 120v
6: When using nitrogen for brazing, the pressure should be:
- Very low
- Slightly below atmospheric
- 125 psig
- 50-100 psig
7: The principle used in continuous type absorption systems is
- Charles's Law
- Boyle's Law
- Ohm's Law
- Dalton's Law
8: What would be the classification for Stop & Shop grocery store?
- Place of assembly
- Large mercantile
- Industrial
- Instituional
9: How many refrigerant classifications are there for flammability?
- 1
- 2
- 3
- 7
10: Most CFC's are
- flammable
- toxic
- inert
- inert but toxic
11: Refrigerants shall be classified by
- maximum permissible quantities of each group
- color codes
- toxicity and flammability
- requirements for commercial, industrial, and residential occupancies
12: What is used to check very low air pressures in air conditioning duct?
- Manometer
- Vacuum gauge
- Anemomter
- Barometer
13: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
- Pressure induced displacement.
- Positive displacement
- Low Pressure displacement
- Non-positive displacement
14: The color code of a tank of ammonia is
- white
- light green
- silver
- lavender
15: Fractionation occurs when
- some of the blended refrigerant evaporates or condenses before the rest of the blend
- when a fraction of refrigerant is added as the full charge
- the pressures increase as the heat load increases
- the pressures decreases as the heat load decreases
16: The solution that is pumped into the concentrator in an absorption chiller is referred to as the
- concentrated solution
- absorbed solution
- weak solution
- strong solution
17: Low temperature systems should have what?
- High pour point
- Low pour point
- High viscosity
- None of the above
18: R22 and 410A operate at the same range of condensing and evaporating temperatures
- true
- false
19: B3 refrigerants are considered
- toxic and highly flammable
- non-toxic but flammable
- non-toxic but non-flammable
- toxic but non-flammable
20: Halo-carbon refrigerants cannot be used with what material?
- Copper
- Stainless Steel
- Magnesium alloy
- Aluminum
21: An oil pressure safety switch should be set at
- 10 to 15 psi below low side pressure
- 5 to 10 psi above low side pressure
- 5 to 10 psi below low side pressure
- 10-15 psi above low side pressure
22: Ammonia (NH3) is a group III refrigerant
- True
- False
23: 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
24: What is the purpose of a surge capacitor on a contactor?
- to provide smoother start/stops
- to protect low voltage equipment
- to keep the contactor pulled in
- to balance the sine waves
25: The Board of Boilers adopts by reference
- Montreal Protocol Safety Code
- the 1997 ANSI/ASHRAE Safety Code
- the MACS Pressure Vessel Code of Massachusetts
- MSCA Code