Course: HET 119 HVACR Electricity II

Lab Assignment

page 1
Week 10 Lab Assignment: Heating 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. Digital Room Thermostat
8. Limit Switch
9. Air Flow Switch
10. Gas Valve
11. Ignition Module
12. 3 Light bulbs for Loads
13. Jumper wires

Scope

This lab will help the student to understand Control Devices and how it is used in Heating electrical circuits. 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 a heating system.
3. Have the instructor to inspect the circuit.
4. Cycle the thermostat and witness the action of the loads.
5. Use a jumper wire to bypass the air flow switch.
6. Witness the action from the thermostat.
7. List of what uses of these controls:
  1. Gas Valve
  2. Contactor
  3. Relay
  4. Transformer
  5. Limit Switch
  6. Thermostat
  7. Remote sensing bulb thermostat
  8. Low Pressure Control
  9. High Pressure Control
  10. Oil Pressure Safety Control
  11. Thermo-Overload

Research Questions

1. Explain the sequence of a refrigeration pump-down system operation.
2. What is the operation and purpose of a refrigerant defrost termination switch.
3. What is the purpose of the low pressure switch?
4. What is the purpose of the liquid line solenoid?

Click on the file below to download the Lab Assignment
- HET 119 Wk 10 Lab.docx (15.75 KB)