Course: HET 119 HVACR Electricity II

Lab Assignment

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Week 11 Lab Assignment: Air Conditioning Control Devices

Recommended Materials
1. Lab Sheet
2. Pencil and paper
3. HVAC Textbook
4. Internet Search
5. Test Board 24”x 24”
6. Wires
7. Room Thermostat
8. Transformer
9. Contactor
10. SPDT Relay 24 Volt coil
11. 3 Light bulbs and fixtures (The lights will be used for the compressor, condenser fan motor, and indoor blower motor)
12. Jumper wires

Scope

This lab will help the student to understand Control Devices and how it is used in electrical circuits in air-conditioning systems. The student will wire controls to loads in combination circuits.

Procedures

1. Follow the diagram posted, use light bulb as the loads.
2. On a test board, wire a circuit as an air conditioning system.
3. Have the instructor specify the controls you will need for this assignment.
4. Have the instructor to inspect the circuit.
5. Cycle the thermostat and witness the action of the loads.
6. Use a jumper wire to bypass the pressure controls if used.
7. Witness the action from the thermostat.
8. Explain what is the purpose of these controls:
  1. Compressor
  2. Condenser Fan Motor
  3. Blower Relay
  4. Transformer
  5. Room Thermostat
  6. Blower Motor
  7. Internal Thermo-Overload
  8. Start Capacitor
  9. Potential Relay
  10. Cooling Anticipator

Research Questions

1. Explain the sequence of an air conditioning system Indoor Fan Relay during the cooling cycle.
2. Why does the compressor and condenser fan motor operate at the same time?
3. In this schematic, what is the purpose of the Control Relay?

Click on the file below to download the Lab Assignment
- HET 119 Wk 11 Lab.docx (73.75 KB)