Course: HET 273 - Pneumatic, Electric and DDC Automation - Spring 2015

Unit 4 Outline

Unit 4 Outline
Unit 4 Outline

Objectives

This week’s assignments will support the HVAC Learner to:

- Understand the need for control systems
- Describe electronic control systems
- Describe pneumatic control systems
- Describe electric control systems
- Describe hybrid control systems

Introduction

Buildings need to provide a comfortable environment for occupants at an economical cost. To achieve this electric, electronic, pneumatic, and hybrid control systems are used. The difference in these systems is the technology used and the precision of control. The HVAC/R technician must master these different systems in order to troubleshoot and make any repairs or provide economical upgrades to existing systems. At this level, the technician may be required to design control strategies for proper operation.

Vocabulary

- Closed Loop
- Low Voltage
- Live Voltage
- Normally Open
- Normally Closed

Learning Objectives

1. HVAC Control System
  1. Describe the need for control systems
  2. Electric Control System
    1. Understand line and low voltage
    2. Describe application
    3. Explain advantages/disadvantages
    4. Explain system operation
    5. Pneumatic control systems
      1. Describe system components
      2. Describe applications
      3. Explain advantages/disadvantages
      4. Explain system operation

1. Electronic Control Systems
  1. Understand voltages used
  2. Describe applications
  3. Explain advantages/disadvantages
  4. Explain system operation

1. Hybrid Control Systems
  1. Describe system components
  2. Describe applications
  3. Explain advantages/disadvantages
  4. Explain system operation

Summary

- Control systems are critical for safe, accurate, economical equipment operation
- The HVAC/R technician must have a thorough understanding of each type of control system
- The hybrid control system is very popular as it is the most economical in retrofitting (upgrading) projects