Topics: All categories in the pool
1: R-12 is
- dichlorofluoromethane
- trichlorofluoromethane
- dichloromethane
- dichlorodifluoromethane
2: 1 Watt = ______ BTU's?
- 3.412
- 4.482
- 12
- 7.216
3: The instrument used to measure the specific gravity of absorption chiller solutions is the
- anemometer
- refractometer
- Psychrometer
- hydrometer
4: "R" represents ___ in the Ohm's law formula
- amperage
- voltage
- capacitance
- resistance
5: The measurement of heat in a particular substance is
- enthalpy
- latent heat
- sensible heat
- specific heat
6: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.
- there is no Group B1 refrigerants
- higher
- the same
- lower
7: Where is an EPR valve located on a multi-evaporator system?
- Suction line of the warmest evaporator
- Suction line at the compressor
- Suction line prior to the accumulator of the lowest temperature system
- Suction line of the coolest evaporator
8: If the compression ratio on a centrifugal compressor rises too high, the compressor will stop pumping and make a loud sound commonly referred to as a
- splurge
- merge
- purge
- surge
9: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 365 psig
- 327 psig
- 255 psig
- 125 psig
10: What is Absolute Zero?
- -640F
- -773F
- -400F
- -460F
11: Fusible plugs shall not be used with pressure vessels of
- 15 square feet or less
- 15 cubic feet or more
- 3 cubic feet or more
- 3 cubic feet or less
12: In an electrical circuit, what is potential measured in?
- Ohms
- Herys
- Amps
- Volts
13: 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
- load-side of the contactor in
- 24 volt secondary side of the Class 2 transformer to the thermostat
- first disconnect in
- breaker panel in
14: How many gallons of water do you need per pound of ammonia?
- 100
- 1
- 10
- 50
15: Megaohm meter's main function is
- to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
- to detect very high resistances to ground of refrigeration or air conditioning compressors
- to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
- Both a and b are correct
16: While the system is operating, the discharge line should be
- too hot to hold by hand
- room temperature
- at the same temperature as the crankcase
- 10-15F warmer than ambient
17: Pressure vessels with an internal volume of 3 cubic feet or more
- shall use fusible plugs
- shall use pressure relief devices
- shall use pressure relief devices or fusible plugs
- do not need pressure relief protection
18: 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
19: A micron is
- one millonths of a centimeter
- a larger unit of measurement than Hg
- one millonths of a micrometer
- one thousandths of a millimeter
20: Halogen refrigerants are corrosive to which type of metal?
- stainless steel
- copper
- black iron
- magnesium
21: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
- low side of the system
- high side of the system
- the vapor side of the system
- the liquid side of the system
22: Which of the following types of oils are hygroscopic?
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene mineral
- both a and b
23: Low-side system leaks in a low-pressure chiller will often result in
- system refrigerant leaking from the system
- nitrogen leaking out of the system.
- water being pulled into the system
- air being pulled into the system
24: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- High suction pressure and high discharge pressure.
- High head pressure and low suction pressure
- Low suction pressure and low discharge pressure
- Low head pressure and high suction pressure
25: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
- 9F
- 21F
- 11F
- 29F