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126 Cards in this Set
- Front
- Back
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At what voltage reading should you get between R and C on a circuit board?
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24V
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Capacitors are checked in microfarads, what meter setting would you use to check a capacitor?
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MFD |
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What voltage would i expect to find on a air handler?
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240V |
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Name all the refrigerant types on your gauges
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R-404A,R-22,R-410A |
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On a multimeter, what does VDC stand for?
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Volts DC |
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Select the four system configurations?
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Package unit,Horizontal or multi-poised, Down-flow,Up-flow
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Select the items that count as proper attire when you arrive at each service call
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Clean shaven or properly groomed facial hair, Proper shoes, Company shirt tucked in
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Select the refrigerant type that is stored in the GREEN colored drum.
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R-22
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Select the refrigerant type that is stored in the ROSE colored drum.
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R-410A |
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The big refrigerant line temperature is 55 degrees and the refrigerant saturation temperature for R-22 is 40 degrees. What is the super-heat?
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15 degrees
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The blue gauge reads the refrigerant saturation temperature in which component?
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Evaporator |
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The high side gauge reads the refrigerant saturation temperature in which component?
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Condensor |
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The PSI on the red gauge is 140 degrees. What is the R-410 temperature ?
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50 degrees
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What am I: A device that automatically regulates temperature, or that activates a device when the temperature reaches a certain point:
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T-stat |
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What am I: A device that is used to enable rotational or linear movement, while reducing friction and handling stress:
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Blower
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What am I: formally defined to be the difference of electric potential between two points of a conductor carrying a constant current of one ampere, when the power dissipated between these points is equal to one watt:
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Volt
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What are the pressure scales on the blue gauge? Check all that apply
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PSI,Inches of mercury
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What color hose connects to the service valve of the big refrigerant line?
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Blue |
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What color is associated with R-410a on your gauges?
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Rose |
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What does AAC stand for?
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Amps AC
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What information can we gather from the data tag?
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Type of refrigerant
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What is the color of the drum used to recover refrigerant
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Gray and Yellow
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What is the pressure range for the high side gauge
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0-800
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What is the voltage reading you should get at the disconnect of a residential condensing unit?
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240V |
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What is the voltage reading you should get at the junction box of a furnace?
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120V |
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What is the yellow hose used for?
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Performing a vacuum and recovering refrigerant
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What voltage reading should you get between R and C on a circuit board?
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24V |
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When brazing copper , a tech should do what to the lines to protect line integrity?
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purge the line with nitrogen
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When charging a system with R-22 you should charge the system as:
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Liquid, vapor, and tacos
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When checking a refrigerant charge with a low super-heat which of the following could the cause?
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Low refrigerant
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Where in the refrigeration system is the heat absorbed into the refrigerant?
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The evaporator
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Where in the refrigeration system is the heat rejected from the refrigerant?
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The condenser
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Which gauge is the compound gauge?
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The blue gauge
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Which hose on your refrigerant gauges is connected to the recovery cylinder?
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Yellow |
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Which of the following can be checked or measured in voltage AC?
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Power at the disconnect
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Which of the following can NOT be measured in amperage?
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Contactor
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Which of the following instruments is usually a compound gauge:
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The low side gauge on a set of refrigerant manifold gauges
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Which of the following instruments is usually referred to as the high side gauge:
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The red gauge
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Which of the following is NOT a part of the condensing unit?
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Heat exchanger
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Which of the following is NOT considered a major component of the 4 system configurations?
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Contactor
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Which of the following would you check using continuity?
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Technician suspects a motor has gone bad, Technician suspect wire integrity has been compromised
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Which readings are needed to calculate super-heat?
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The blue gauge and the big refrigerant line
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Which refrigerant line is insulated ?
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The suction line
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Which refrigerants types are depicted on your gauges?
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R-410 A, R-22
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You should never fill your recovery tank more than __ to allow room for expansion
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80% |
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Your compound gauge reads a saturation temperature of 60 degrees for R-22. What is the corresponding PSI.
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100 psi
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Your red gauge read 270 PSI. What is the corresponding temperature for R-410a.
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90 degrees
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Which of the following is not considered a safety?
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Gas Valve
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Which of the following's only purpose is to protect the transformer?
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Fuse
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What should the gas pressure be on a furnace that uses propane?
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10.5
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True or False: A standing pilot furnace has an inducer motor.
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False
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What should the flue pipe pitch be for a condensing furnace?
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1/4
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What type of transformer has more turns in the primary winding than in the secondary winding?
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Step-down Transformer
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If you set the thermostat for a call for heat and nothing happens, what two wires would you check?
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W AND C
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What is the applied voltage for the gas valve?
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24V |
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Which setting on a multi-meter is used to check batteries?
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VDC
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What does the roll out switch do?
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Locks furnace out in case of a flame roll out
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What is the purpose of an 80% furnace inducer fan motor?
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To remove flue gases from the furnace, To create a negative pressure
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What type of circuit is the high limit and the rollout switches wired in?
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Series
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Which color wire is used for the reversing valve of a heat pump?
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Orange
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If you set the thermostat for a call for heat and nothing happens, what two wires would you check?
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W and C
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What are the terminals of a Thermostat?
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R, W, G, Y, C, O
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Which of the following is a characteristic of an 80% furnace?
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Metal flue pipe
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Which multi-meter setting is used to check the resistance of an igniter?
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Ohms
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Which setting on the thermostat will cause the blower to run continuously?
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On
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What gauge wire is typically used for installing thermostats?
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18 gauge
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What is the primary to secondary winding ratio of a transformer with a primary voltage of 120 and a secondary voltage of 24?
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5:1
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What units of measurement do we use to measure gas and static pressure?
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Inches of water column
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What component does the transformer supply power to?
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Control Board
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What is the one item that a technician does not need to know when replacing a transformer?
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Wire size
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Why is it important to level a digital thermostat?
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Aesthetics
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What type of pressure does the inducer motor create inside the heat exchanger of an 80% furnace?
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Negative
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What does the high limit switch do?
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Locks down furnace to prevent heat exchanger overheating
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Which grade steel wool is used to clean a flame sensor?
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000 |
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What would the voltage be between R and W during a call for heat?
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24V
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When should a furnace filter be changed?
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When it is dirty
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What is the color of the control wire used to represent heat?
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White |
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With the system operating: which meter setting is used to check the flame sensor?
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Micro-Amps DC
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What is the applied voltage for the pressure switch?
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24V |
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Which tool is used to check the gas pressure leaving the Gas Valve?
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Manometer
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Which of the following is not a characteristic of a 90% furnace?
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Metal flue pipe
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What does a flame sensor do?
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Proves a flame is present
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Which multi-meter setting can be used to check the High Limit Control?
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Continuity
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What is the applied voltage for the inducer motor?
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120V |
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What type of contacts does a pressure switch have?
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Normally open |
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What does the Pressure Switch do?
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Proves the inducer motor is working
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What color thermostat wire is used for power?
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Red
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What is the most common manifold gas pressure for natural gas?
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3.5 inches of water column
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Which multi-meter setting is used to check the capacitor?
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MFD |
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How many wires are used to install a conventional thermostat?
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5 |
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Which meter setting is used to check the Inducer Motor?
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Amps |
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What is the applied voltage for the blower?
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120V |
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Choose the component that is wired in series with the high limit control?
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Roll out switch |
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What is the formula to calculate wattage of electric heat strips?
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Volts * Amps = Watts
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What color thermostat wire is used for the blower?
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Green
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What is the applied voltage for the igniter?
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120V
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Which manufacturer uses B for the reversing valve (unlike all other manufacturers
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Rheem/Ruud
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What is the function of a crankcase heater?
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To prevent refrigerant migration to the compressor during the off cycle.
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When a heat pump goes into defrost mode, what terminal does the defrost board energize to prevent cold air from blowing in the house
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W |
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What is the minimum PSI required for a reversing valve sliding mechanism to move?
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50 PSI |
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Which TXV is bybassed in Heating mode?
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Indoor
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If a heat pump is installed in a high snow area, which accessory should be installed
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Snow legs
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In the heating mode, a dirty filter will cause a heat pump to
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Lock out on high head pressure
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What terminal designation do all other manufacturers use for the reversing valve
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O |
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What is the purpose of an accumulator?
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To ensure 100% vapor refrigerant enters the compressor
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What color is the reversing valve control wire normally?
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Orange |
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A reversing valve will not function properly when
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Refrigerant level is low
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What is the state of the refrigerant at the true suction port?
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Low pressure vapor
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Which color wire is not connected to the defrost control board from the air handler?
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Green |
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Where is the condenser coil on a heat pump in the heating mode
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Indoor |
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In defrost mode, the reversing valve switches to cooling mode and the auxiliary heat is energized. What else happens?
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The condenser fan is de-energized
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A heat pump outdoor unit must be level. Why?
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Prevent oil from collecting, To prevent ice buildup, For proper drainage
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How many control wires are needed at minimum to the outdoor unit
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5 |
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Which coil receives hot gas refrigerant in cooling mode?
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Outdoor coil |
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How many volts are applied to the reversing solenoid?
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24V |
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When in the heating mode, where is the discharge gas from the compressor routed.
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Indoor Coil |
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What can De-energize in De-frost mode? |
De-frost timer |
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What is the reason for he 1/4 inch pitch on pvc ventline? |
To allow condensation to fall back to the furnace for draining. |
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When would you discuss repair v.s. Replacement with the customer? |
For any major repair |
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What is one of the biggest causes of no charge tickets? |
A tech not doing a thorough assessment of system needs |
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What is the best method to use for detecting small leaks? |
Electronic leak detector |
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If we have a low to 0 superheat and a good us cool,what is the cause? |
Dirty filter |
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Schedule 40 pipe is also known as? |
PVC for the flue pipe |
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If you discover a need for IAQ products what does it go under? |
Investigative findings |
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If it is hot What will happen to recovery ? |
It will take longer |
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What does AFUE stand for |
American Fuel Usage Efficiency |
