Topics: All categories in the pool
1: The heat picked up in the evaporator must equal to
- the heat giving by the condenser
- the heat of compression
- the heat lost by the medium being cooled
- the heat gained by the condenser
2: Ammonia shall be discharged into ____________ or a tank containing one gallon of water for every pound of ammonia.
- the atmosphere
- a de-pressurized recovery tank with a silver top and yellow bottom
- a tank containing two pounds of a water/lithium bromide mix for every pound of ammonia
- All of the above
3: On a centrifugal compressor, stationary diffuser vanes are needed to
- increase the clearance space
- convert velocity energy to pressure
- prevent high pressure on the packing
- stop gas flow
4: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- centrifugal switch
- printed circuit board (PCB)
- motor starter
- duel-voltage switch
5: A chilled water pump's suction gauge reads 10 psig. The discharge gauge reads 48 psig. What is the head in feet the pump is working against?
- 38
- 96
- 88
- 58
6: No open flames are allowed in the machinery room unless?
- Approved by the installing contractor
- Never can be allowed
- Only when combustion air is provided from outside of the machinery room
- Approved by the authorized person
7: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- .8
- 1.7
- 1.2
- .1
8: Increasing superheat will do what to your frost line?
- Could either increase or decrease depending on the load conditions
- Increasae
- Decrease
- Nothing
9: A motor starter contains a thermal overload and a
- contactor
- transformer
- 3-way relay
- solenoid
10: Where a refrigeration or air conditioning system is installed,
- A field inspection shall be made before it is put into service
- the form or certificate shall be authorized by the Department of Public Safety
- The company who installed the system must notify the fire department in the jurisdiction where installed
- it shall not be operated below prescribed pressuers
11: The density of a gas refers to
- pounds per absolute pressure
- cubic feet per pound
- pounds per cubic foot
- pounds per square foot
12: When an electronic bridge is in balance the bridge output will be
- 15 volts
- .01 volts
- 1 volt
- 0 volts
13: Capacitors are rated in
- kelvins
- micro-farads
- megaohms
- volt - amperes
14: E = I X R is
- Ohms Law
- Amps Law
- Impedance Law
- Watts Law
15: On a day with low relative humidity, the two thermometers on a sling psychrometer will read
- far apart or greater difference
- 2F difference
- a ling psychrometer doesn't have two theremometers.
- nearly the same
16: Adjusting the spring pressure on a TXV
- makes no difference
- changes subcooling
- adjusts the bulb charge
- changes superheat
17: What type of refrigerants are NOT flammable?
- CHC
- HFC
- HCFC
- All of the above
18: A restaurant is classified as a
- commercial occupancy
- mixed occupancy
- large mercantile occupancy
- public assembly occupancy
19: What type refrigerant is NOT ozone depleting?
- HCFC
- HFC
- Halon
- CFC
20: 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 release a sticking valve
- to sweat flanges on the refrigeration piping
21: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is
- Latent heat
- Specific heat
- Enthalpy
- Sensible heat
22: Pressure vessels with an internal volume of 3 cubic feet or more
- shall use pressure relief devices or fusible plugs
- do not need pressure relief protection
- shall use pressure relief devices
- shall use fusible plugs
23: Secondary refrigerants are usually
- expensive
- alcohol
- Prestone anti-freeze
- water or brine
24: Absolute pressure is
- Gauge Pressure
- Atmospheric Pressure
- Gauge + Atmospheric Pressure + Pi
- none of the above
25: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- Nothing must be done
- Place sign, check for leaks, and insulate suction line
- Make sure its compatible, notify owner, and notify AHJ.
- you can never change refrigerants