Click on “Download PDF” for the PDF version or on the title for the HTML version.


If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

RELAY-BASED CONTROL SYSTEMS

Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org

Citation:   (doi:10.13031/2013.17769) in Relay-Based Control Systems. Chapter 9 in Fundamentals of Electricity for Agriculture, 3rd edition, 249-275. St. Joseph, Michigan: ASAE. . Copyright 2004 American Society of Agricultural and Biological Engineers, St. Joseph, Mich.
Authors:   Gustafson, Robert J., and Mark T. Morgan
Keywords:   Relay Principles, Time-Delay Relays, Relays vs. Electromagnetic Contactors, Magnetic Motor Starters, Ladder Logic Diagrams, Reduced Voltage Control and Overload Contacts

Previous control system examples only showed switches that directly controlled the load. In this chapter, we will examine relay-based controls that allow larger electrical loads such as motors to be controlled indirectly for improved safety and flexibility. We will start by explaining the construction and function of relays, magnetic contactors, and motor starters, and then cover the common language of relay-based controls known as ladder logic diagrams.

    After studying this chapter, you should be able to:
  • Explain the operation of relays,
  • Explain the differences between control relays, magnetic contactors, and motor starters,
  • Explain how and why overload protection is required for motor controls,
  • Understand ladder logic diagrams, and
  • Design basic control circuits using standard symbols and ladder logic diagrams.

(Download PDF)    (Export to EndNotes)

 

Authors, please use the Guide for Authors when creating your articles.

Public Access Information
 Public Access = Public Access (PA)
 Public Access Limited Time = PA Limited Time
 Open Access = Open Access
 Contact Us For Purchase = Contact Us For Purchase