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21 Cards in this Set
- Front
- Back
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What type of controls are used by the driver to turn the system on and adjust air conditioning, airflow direction, and velocity Active passive, supplemental mandatory |
Active |
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What type of controls regulate the flow of air conditioning refrigerant or heater coolant without Driver input Active Passive Supplemental Mandatory |
Passive |
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What type of controls may prevent or support system functions? Active Passive Supplemental Mandatory |
Supplemental |
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The blower speed switch has three on positions to control, blower fan, speed, and regulate the HVAC system, air velocity which is measured in SFM ,BTU, psi ,CFM |
CFM |
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The engine coolant water valve is a Pass of control that allows the operator to set the amount of hot engine coolant. I will pass through the heater core. |
False the engine coolant water valve is an active control |
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Siezed open emgine coolant water valve will cause the truck cab to remain very warm even when the trucks air conditioning is operating when warm spring and summer weather occurs |
True this is a major problem, every spring in northern climates |
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A 12 V electricromagnet clutch coil is indicated by Blue lead wire Greenlead wire Black lead wire White lead wire |
Black lead wire |
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The first pass of control in the electrical circuit that energizes the compressor electromagnetic clutch is a Thermostatic switch Low pressure switch High pressure switch Ambient temperature switch |
Thermostatic switch |
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When the air conditioning system contains a fixed expansion tube, and an accumulator, the thermostatic switch may be replaced with a Ambient temperature switch High pressure switch Clutch cycling switch Binary switch |
Clutch cycling switch |
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Refrigerant, low pressure, sensing switches are used on thermostatic expansion valves, equipped air conditioning systems as a low ambient temperature protection, switch, true or false |
True the ambient temperature switch will protect the air conditioning compressor from operating with very l hello refrigerant pressures and a lack of oil circulation |
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The pressure setting of a high-pressure switch must be adjusted_____________ the settings of a refrigerant pressure, relief valve or fusible plug Lower than The same as Higher than Much higher |
Lower than |
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The binary switch acts like a____________ switch Low pressure High pressure Ambient temperature all the responses are correct |
All responses are correct |
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How many functions does the trinary pressure switch perform to monitor and control refrigerant pressure inside the air conditioning system? One Two Three Four |
Three |
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List the two devices used to control, refrigerant flow into the evaporator core |
Thermal expansion valve Fixed orifice tube |
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What electrical device is used in HVAC systems to control fan or blower motor speed Circuit breakers SPST Relay Resistor |
Resistors |
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List the two types of blower wheels that are used in HVAC systems |
Single entry blower wheel’s double entry blower wheels |
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A heater system uses____________ to carry excess engine heat energy to warm the cab |
Engine coolant |
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List, the three inputs of an air conditioning management system |
High pressure switch, low pressure switch, evaporator thermostatic switch |
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What’s the three outputs of an automatic temperature control system? |
The heater water control valve, the fan blower motor, the air conditioning system compressor |
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The doors and an HVAC duct system can be controlled by Push or pull cables Vacuum motors Compressed, air motors Electric motors All of the above |
All of the above |
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Front (Term) |
Back (Definition) |
