Topics: All categories in the pool
1: Ammonia vaporization takes place at what temperature?
- -32F
- -28F
- -110F
- -460F
2: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.
- CFC-11
- HCFC-123
- ammonia
- Lithium bromide
3: Foaming of oil in a compressor is most likely to occur
- when there is insufficient air across the condenser(i.e., dirty coil)
- when the evaporator temperatures are below 32F
- at start-up
- when ambient temperature are low
4: A start capacitor is wired in _____ with the start windings.
- parallel
- junction
- series-parallel
- series
5: Heat transferred by conduction from one body to another is done via:
- gas
- liquid
- solid
- All of the above
6: When is the only time you can leave a service container attached to a system?
- Leaking system
- Recovery
- Charging
- Both b and c
7: R-123 belongs to Group
- A-3
- B-3
- B-2
- B-1
8: Which of the following types of oils are hygroscopic?
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene mineral
- both a and b
9: 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
10: RPM's of a centrifugal compressor are at approximately?
- 500
- 30,000
- 10,000
- 15,000
11: Which is considered the more efficient condenser?
- air cooled
- spray cooled
- fan cooled
- water cooled
12: Where a refrigeration or air conditioning system is installed,
- the form or certificate shall be authorized by the Department of Public Safety
- A field inspection shall be made before it is put into service
- The company who installed the system must notify the fire department in the jurisdiction where installed
- it shall not be operated below prescribed pressuers
13: Whoever owns/uses a refrigeration or air conditioning system covered by this code
- must notify the Department of Public Safety prior to starting the system
- shall be licensed by the Commonwealth of Massachusetts according to CMR 522
- shall make application for inspections to the Chief of Inspectors
- None of the above
14: What type of relief valve is used on a CO2 system?
- gate valve
- glove disc
- fusible plug
- rupture disc
15: "E" references ____ in the Ohm's law formula
- capacitance
- voltage
- amperage
- resistance
16: A moisture indicator must
- change color when exposed to moisture
- be sight side up
- be yellow
- be filled with liquid
17: Who approves containers for refrigerants?
- D.O.T
- D.O.E
- E.P.A
- D.O.D
18: A person holding a license as a refrigeration technician may connect or disconnect for the purpose of installation, repair, or replacement, any electrical device or control to be a part of a refrigeration or air conditioning system, from the
- breaker panel in
- 24 volt secondary side of the Class 2 transformer to the thermostat
- load-side of the contactor in
- first disconnect in
19: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
20: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
21: When a refrigeration or air conditioning system is installed
- a field inspection shall be made before it is put into service
- the form of certificate shall be authorized by the Department of Pubic safety
- it shall not be operated below prescribed pressures
- it shall be approved by the owner for proper operation.
22: A micron is
- one thousandths of a millimeter
- one millonths of a centimeter
- a larger unit of measurement than Hg
- one millonths of a micrometer
23: The oil separator is always inserted in the system
- where it can be easily serviced
- to prevent oil logging
- in a cool spot
- in the discharge line
24: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 90%
- 80%
- 75%
- 99%
25: Color is important in oil because
- allows you to see into crankcase
- it makes sight glasses easy to read
- can tell us something about the refining of oil
- it indicates the viscoisty.