Topics: All categories in the pool
1: Liquid line filter-driers on a 410A system must be rated for no less than
- 200 psig
- 600 psig
- 400 psig
- 1000 psig
2: A cross charged power element on an expansion valve would normally be used in what temperature range?
- 30F to 50F
- -100F to -40F
- 0F-38F
- -40F to 0F
3: In designing duct work, pressure and ______ need to be considered
- length
- CFM
- duct sealant used
- all of the above
4: Booster compressors connect to the ____ side of the compressor
- vapor
- low side
- oil side
- liquid
5: How many refrigerant classifications are there for flammability?
- 3
- 7
- 2
- 1
6: When energized, a normally open relay will be
- noisy
- depends on the type and class of the relay
- open
- closed
7: Refrigerant restricted in 2004 but used for transition for decades:
- R-22
- R-11
- R-134A
- R-123
8: A split-phase motor has a ______ winding and a ____ winding
- duel-run, duel-start
- run, common
- start, common
- run, start
9: 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
- licensed technician
- competent welder
- licensed welder
10: The actual expansion curve of compressor follows most nearly which one of the following
- Pressure-Temperature
- Adiabatic
- Volume
- Isothermal
11: Fusible plugs shall not be used with pressure vessels of
- 15 square feet or less
- 3 cubic feet or less
- 15 cubic feet or more
- 3 cubic feet or more
12: The evaporator is a device to
- store liquid refrigerant
- remove heat from the refrigeration system
- Keep the compressor busy
- absorb heat into the refrigeration system
13: A motor starter contains a thermal overload and a
- contactor
- transformer
- 3-way relay
- solenoid
14: Ammonia shall be discharged into ____________ or a tank containing one gallon of water for every pound of ammonia.
- the atmosphere
- a de-pressurized recovery tank with a silver top and yellow bottom
- a tank containing two pounds of a water/lithium bromide mix for every pound of ammonia
- All of the above
15: On a 460V motor, what is he MAXIMUM voltage that can be safely applied to it?
- 506v
- 550v
- 660v
- None of the above
16: Pairs of mating stop valves that allow sections of a system to be joined before opening these valves or separated after closing them are
- king valves
- gate or globe valves
- ball valves
- companion or block valves
17: Where a refrigeration or air conditioning system is installed,
- the form or certificate shall be authorized by the Department of Public Safety
- it shall not be operated below prescribed pressuers
- The company who installed the system must notify the fire department in the jurisdiction where installed
- A field inspection shall be made before it is put into service
18: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
- 1.2
- 1.5
- 2.2
- 1
19: Suction valve unloaders afford an effective means of
- capacity control
- refrigerant control
- evaporator control
- superheat control
20: All electrical work done on refrigeration systems must comply with
- ASHREA-15 Section 9.2.1
- OSHA
- NEC and Massachusetts Modifications
- Department of Energy
21: Which of the following controllers would you expect to be most sensitive to temperature changes?
- low voltage t-stat
- line voltage t-stat
- immersion controller
- aquastat
22: Secondary refrigerants are usually
- water or brine
- alcohol
- Prestone anti-freeze
- expensive
23: Class T machine room
- shall include closets used for setting equipment
- has no flame producing apparatus permanently installed
- shall have remote controls to stop the action of the refrigerant compressor
- shall have refrigerant leak detecting systems installed inside and outside the room
24: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- motor starter
- printed circuit board (PCB)
- centrifugal switch
- duel-voltage switch
25: Fractionation occurs when
- some of the blended refrigerant evaporates or condenses before the rest of the blend
- the pressures increase as the heat load increases
- the pressures decreases as the heat load decreases
- when a fraction of refrigerant is added as the full charge