Title: Unit 9 Outline
Course: HET 119 HVACR Electricity II > Section: HET 119 HVACR Electricity II

Unit 9 Outline

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Unit 9 Outline

1. Control Voltage

Transformer
- Primary Coil
- Secondary Coil
- Turns and Voltage Relationship

Types of Transformers
- Step Down Transformers
- Step Up Transformers
- Ratings of Transformers

2. Thermostats

Types of Thermostats

Low Voltage Thermostats
- Anticipators

3. Pressure Controls, Time Delay Relays, Float Controls, Flow Controls, and Time Clocks

Purpose of Controls

Operations of Controls

4. Electronic Controls

Benefits of Electronic Controls

Uses of Electronic Controls

Summary

- Control Devices are the part of an electrical system to operate when, how, where, and what will be turned on, off, and by a variable signal.
- HVAC/R systems need to control the temperature, pressure, flow, humidity, and level for the comfort of humans; thereby, it will be necessary to know all possible sequence of operations of a HVAC/R system.
- Controls can be binary (off and on), analog (variable), or integral (variable and adjusting) controls to give the most efficient control of a HVAC/R system.
- Most control system use low voltage operating at 24 Volts and uses a transformer to step down the voltage.

Review the vocabulary terms listed below and look up their definitions / descriptions before taking the Vocabulary Quiz.

Vocabulary

- Thermostat
- Pressure Control
- Humidistat
- Air Flow Switch
- Binary
- Analog
- Control Device
- Controlled Device
- Integral Control,
- Anticipators
- Time Clock
- Transformer
- Solenoid Valve