Topics: All categories in the pool
1: Sensible heat is the heat added to a substance to
- freeze it
- change its state
- cause evaporation
- raise its temperature
2: 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
- 24 volt secondary side of the Class 2 transformer to the thermostat
- load-side of the contactor in
- breaker panel in
- first disconnect in
3: 746 watts is equal to
- Pi
- 10 hp
- 100 hp
- 1 hp
4: Low ambient controls are used when
- always
- when systems run all year round
- economizers are used
- on air conditioning systems only
5: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- overcharged
- starved evaporator
- compressor suction valve stuck open
- too small evaporator
6: What is NOT a positive displacement compressor.
- Centrifugal
- Rotary
- Scroll
- Reciprocating
7: Each machinery room shall contain
- high and low pressure controls
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
8: A restaurant is classified as a
- public assembly occupancy
- mixed occupancy
- commercial occupancy
- large mercantile occupancy
9: Name three things that must be done when changing refrigeration lubricant?
- You can't change lubricants.
- Place sign, check for leaks, insulate
- Nothing must be done
- Make sure it's compatible, notify owner, notify AHJ
10: Pressure is the equivalent of
- force
- area times force
- force times area
- force per unit area
11: A pressure vessel having an inside diameter of 6” or less shall be sufficient to withstand ____times the pressure of the saturation temperature of the refrigerant or ____times the critical pressure of the refrigerant, whichever is less.
- 2.5, 2.5
- 6.6, 6.6
- 2.5, 3.0
- 3.0, 3.5
12: Which refrigerant class listed below is the most flammable?
- C-3
- A-1
- A-3
- B-2
13: Where are the three places that the discharge from an ammonia relief valve be piped?
- atmosphere, tank containing water, where the A.H.J. indicates
- underground, into drain, into mechanical room
- to chemical neutralizing tank only
- none of the above
14: The proper location for an oil separator is between the
- condenser and receiver
- compressor and condenser
- evaporator and compressor
- receiver and metering device
15: How many opening forces operate a thermostatic expansion valve?
- 2
- 1
- 4
- 3
16: Booster compressors, pump refrigerant into the
- high side of the secondary compressor
- low side of the primary compressor
- heat & plate heat exchanges
- receiver
17: R-22 is classified as a ____ refrigerant on the safety matrix.
- B-1
- A-1
- B-2
- A-2
18: What is the voltage of each leg of a 480 Volt three-phase motor?
- 120v
- 277v
- 208v
- 240v
19: A 3-cubic foot receiver must have what type of relief valve?
- fusible plug
- relief valve
- rupture device
- none of the above
20: A normal operating evaporator temperature of R-22 for air conditioning is typically
- 32F
- 45F
- 55F
- 58F
21: The location of a thermal bulb of a TXV affects
- the amount of liquid in the condenser.
- the amount of liquid refrigerant in the evaporator
- subcooling
- the amount of liquid returning to the compressor
22: What is not a requirement of a Class T machine room?
- Tight fitting doors
- Automatic ventilation
- Fire hose connected to the building fire protection system.
- Self-closing doors
23: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
- low head pressure
- oil in evaporator
- moisture in the system
- not enough oil in the system
24: 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
25: What is the minimum height refrigeration piping should be placed against walls?
- Ceiling height
- 7.25'
- 72"
- 6'