Topics: All categories in the pool
1: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
- 9F
- 21F
- 29F
- 11F
2: Capacity control on a centrifugal compressor is accomplished by the
- post-rotational guide vanes
- slide vanes
- pre-rotational guide vanes
- check valves
3: Dual-pressure relief devices should be installed on
- vessels of 10 cubic feet or more
- vessels of 3 cubic feet or less
- vessels of 3 cubic feet or more
- vessels of 10 cubic feet or less
4: The discharge relief valve is located (9.4.6)
- on top of the condensor
- between the compressor and the stop valve
- between the compressor and oil separator
- between the compressor and reciever
5: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b
6: A “U” or “UM” marking a on a nameplate of a pressure vessels signifies compliance with Section VIII of
- the ASME Boiler and Pressure Vessel Code
- Section 11.3.1.5 ASHRAE 15 Standard
- the ANSI Standard 10.7.2
- both the ANSI Standard 10.7.2 and ASHRAE 15 Standard 11.3.1.5
7: When can 50/50 solder be used?
- in the low side
- in the high side
- liquid and suction lines
- none of the above.
8: Megaohm meters can detect a ground in the
- up to 1,000 ohms
- 10,000,000 ohms or higher
- up to 10,000 ohms
- up to 1,000,000 ohms
9: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
- latent heat
- specific heat
- sensible heat
- lost heat
10: A start capacitor is wired in _____ with the start windings.
- series
- junction
- series-parallel
- parallel
11: Which oil is hydoscopic?
- mineral
- animal
- SW30
- polyolester
12: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 327 psig
- 365 psig
- 255 psig
- 125 psig
13: Color is important in oil because
- it indicates the viscoisty.
- can tell us something about the refining of oil
- allows you to see into crankcase
- it makes sight glasses easy to read
14: Pressure is the equivalent of
- area times force
- force
- force per unit area
- force times area
15: Pressure vessels shall be provided with ___________in accordance with Section VIII of the ASME Boiler & Pressure Vessel Code
- Pressure vessels need no type of protection as long as it is hydrostatically tested every three months
- over pressure protection
- over pressure protection and a rupture disc
- over pressure protection as well as a temperature protection device
16: Volts x amps equals
- Watts
- Ohms Law
- Impedance
- Inductance
17: The measurement of heat in a particular substance is
- sensible heat
- enthalpy
- latent heat
- specific heat
18: Halogen refrigerants are corrosive to which type of metal?
- black iron
- copper
- stainless steel
- magnesium
19: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.
20: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 44 lbs
- 22 lbs
- 13.9 lbs
- 6.6 lbs
21: A hotel is considered a _______ occupancy.
- residential
- institutional
- commercial
- mercantile
22: What device should be used on low-temperature freezers?
- oil separator
- high capacity TXV
- discharge muffler
- hot-gas by-pass
23: Give an example of a secondary coolant?
- R-717
- R-12
- R-410A
- R-718
24: The main purpose of a refrigerant detector in a machinery room is to
- inform there is a refrigerant leak int he system
- detect toxins in the air caused by a refrigerant leak
- to set off an alarm when there is refrigerant present inside the room
- all of the above
25: The color code of a tank of ammonia is
- white
- light green
- lavender
- silver