Electricity unit 18 review

A service technician should never leave a conditioned air system with a safety control device ____________________.

• Removed from the circuit

• Jumped out

• Replaced with the incorrect part

• All of the choices are correct

Damaged low-voltage control wiring can cause which of the following conditions to occur in an air conditioning control system?

• Multiple functions to operate at the same time

• Some or all systems functions may not operate

• Blown low voltage fuses or control transformer damage

• All of the choices are correct

Many newer HVAC systems often convey fault and system status codes to technicians by using a(n)_____________________.

• Audible voice notification

• Blinking light

• Audible beep

• Diagnostic computer

The capacitance reading of a good running capacitor should be within ____________ of the capacitance required by the motor.

• 10%

• 20%

• 25%

• 50%

What component should a service technician check if line-voltage is available to an HVAC unit, but no low-voltage is present at the control circuits?

• Contactor coil

• Compressor motor

• Transformer

• Thermostat

What is the condition of a single-phase compressor if a technician reads a resistance of infinity (OL) between the “common” and “run” terminals of a hermetic compressor?

• Open run winding

• Shorted run winding

• Good run winding

• Closed internal overload

What is the condition of the coil on a 230-volt relay with a resistance reading of OL on a digital ohmmeter?

• The coil is good

• The coil is open

• The coil is shorted

• The coil is shunted

What is the purpose of a troubleshooting chart?

• A guide to help the homeowner troubleshoot and repair their HVAC unit.

• Aid the technician in reading wiring diagrams enabling them to troubleshoot electrical problems in HVAC equipment.

• Guide the technician through a systematic approach to troubleshooting HVAC systems.

• Help the installation technician to use proper installation techniques.

What knowledge must a service technician possess to troubleshoot and diagnose problems with HVACR systems effectively and correctly?

• How to read and interpret schematic diagrams

• How the unit should operate normally

• How to correctly use and read electrical test instruments

• All of the choices are correct

What must a person know and understand about an air conditioning system in order to be an effective service technician?

• How the system operates

• Why the equipment operates as it does

• When the functions of the system should operate

• All of the choices are correct