Topics: All categories in the pool
1: Adjusting the spring pressure on a TXV
- adjusts the bulb charge
- changes subcooling
- changes superheat
- makes no difference
2: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 365 psig
- 255 psig
- 327 psig
- 125 psig
3: A chilled water pump suction gauge reads 10 psig. Discharge gauge reads 48 psig. The head in feet of the pump is working against
- 108
- 116
- 88
- 38
4: How are safety controls wired in a circuit?
- Either series or parallel
- Series/parallel
- Series
- Parallel
5: An example of an "Expendable Refrigerant" is
- liquid nitrogen
- lithium bromide
- liquid oxygen
- ammonia
6: When testing systems using non-positive displacement compressors, the entire system shall be considered for test purposes as the low side.
- True
- False
7: A halide torch is most useful with a freon compression system
- to sweat flanges on the refrigeration piping
- to remove from from TXV's and evaporator coils
- to detect refrigeration leaks in piping joints
- to release a sticking valve
8: Machinery rooms must be vented to ______?
- outdoors
- unoccupied spaces
- neutralizing tank
- basement
9: A 3-cubic foot receiver must have what type of relief valve?
- fusible plug
- relief valve
- rupture device
- none of the above
10: How can you test mechanical strength of an electrical connection?
- measure ohms with an electrical meter
- measure voltage across the connection
- attempt to pull the wire from the connector by hand
- none of the above.
11: Pressure vessels with an internal volume of 3 cubic feet or less
- shall use pressure relief devices
- shall use fusible plugs
- do not need pressure relief protection
- shall use pressure relief devices or fusible plugs
12: Low ambient controls are used when
- on air conditioning systems only
- always
- economizers are used
- when systems run all year round
13: What type of material can't be used on the outlet of a relief valve?
- Magnesium alloy
- Stainless steel
- PVC
- Copper
14: What type of voltage causes the winding in a potential relay to open?
- BEMF (Back Electro-Motive Force)
- 24V control voltage from the thermostat
- 120V line voltage
- None of the above
15: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 22
- 50
- 25
- 66
16: Where a refrigeration or air conditioning system is installed,
- The company who installed the system must notify the fire department in the jurisdiction where installed
- it shall not be operated below prescribed pressuers
- 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
17: Which of the following is an inorganic refrigerant?
- R-22
- Ammonia
- Chlorofluorocarbons
- All of the above
18: Booster compressors connect to the ____ side of the compressor
- vapor
- oil side
- low side
- liquid
19: R-22 is considered a(n)
- HFC
- HCFC
- CFC
- HCFCH
20: The first step in mechanical refrigeration is
- condensation
- compression
- evaporation
- expansion
21: Transformers are rated in
- volts-ohms
- amps
- volt-amps
- volts
22: What device should be used on low-temperature freezers?
- oil separator
- discharge muffler
- hot-gas by-pass
- high capacity TXV
23: What effect does the temperature of air have on humidity?
- warmer air holds more moisture then cooler air
- cooler air holds more moisture then warmer air
- air has no effect of humidity
- none of the above
24: Materials used in construction and installation materials used in the manufacture or installation of refrigerating equipment shall be suitable for conveying refrigerant and the refrigerant oils and will not deteriorate in the presence of what?
- Moisture and air
- Oil and water
- Water and soap
- Air and dirt
25: A premise where large numbers of people congregate and from which occupants can not quickly vacate the space is considered
- mixed occupancy
- institutional occupancy
- commercial occupancy
- public assembly occupancy