Topics: All categories in the pool
1: Low pressure systems have what kind of compressor?
- Scroll
- Rotary
- Centrifugal
- Reciprocating
2: How many BTU's is produced by one watt of energy
- 3.00
- 1
- 2.57
- 3.41
3: Capacitors are rated in
- volt - amperes
- megaohms
- kelvins
- micro-farads
4: Lithium-bromide, Li-Br, is best characterized as a
- sugar
- soil
- sand
- salt
5: The low pressure oil safety switch
- must be reset manually
- never trips
- resets itself automatically
- resets itself after the time delay has terminated
6: The rupture disc on a low-pressure chiller typically releases pressure at
- 15 psig
- 5 psig
- 10 psig
- 0 psig
7: What's the most efficient condenser type?
- Shell and tube
- Air cooled fins
- Both are equal in efficiency
- None of the above
8: How is bring measured?
- hygrometer
- anemometer
- manometer
- hydrometer
9: Atmospheric pressure is equal to
- 29.92" Hg
- 14.7 psia
- 14.7 psig
- both a & b
10: When should a relief valve start to function?
- Two times it's working pressure
- Before the purge station discharges
- 10 psi before it's set pressure
- At it's set pressure
11: If you have a motor of 2 HP or less and under 300V, you can use a single pole switch (snap switch) with at least what rating?
- 5x FLA
- 2x FLA
- 1x FLA
- 4x FLA
12: A halide torch is most useful with a freon compression system
- to detect refrigeration leaks in piping joints
- to remove from from TXV's and evaporator coils
- to sweat flanges on the refrigeration piping
- to release a sticking valve
13: Pi equals approximately
- 3.41
- 12,000
- 746
- 3.14
14: What type of fuses must be used on a HVAC system?
- TR Type, Duel Element, Time Delay
- Fast blow
- 10% lower than RLA
- none of the above
15: What would be the classification for Stop & Shop grocery store?
- Large mercantile
- Place of assembly
- Instituional
- Industrial
16: What do you need to do when you install a new system?
- Have it inspected
- Add refrigerant
- Insulate the suction line before you take a superheat reading
- Document the superheat and subcooling reading
17: The actual expansion curve of compressor follows most nearly which one of the following
- Pressure-Temperature
- Volume
- Isothermal
- Adiabatic
18: An electronic bridge circuit is basically a
- 24 volt control circuit
- Wheatstone
- high voltage circuit
- suspension
19: A Lithium-bromide system is an absorption system that
- uses water as a refrigerant and lithium bromide as an absorbent
- uses ammonia as a refrigerant and lithium bromide as an absorbent
- uses water as a absorbent and lithium bromide as a refrigerant
- uses salts as an absorbent and lithium bromide as a refrigerant
20: If the power element on an expansion valve should lose its charge, the valve would
- Under feed
- Over feed
- Close
- Stay open
21: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Saturated temperature
- Critical temperature
- Wet bulb temperature
- Dry bulb temperature
22: Liquid level gauges must be provided with what?
- A low level mark
- A relief valve
- Automatic shut-offs
- A red line
23: RPM's of a centrifugal compressor are at approximately?
- 30,000
- 500
- 10,000
- 15,000
24: A tachometer is an instrument used to measure
- RPM
- static pressure
- air velocity
- speed
25: Name an HCFC refrigerant(s):
- R-22
- R-123
- R-11
- both a & b