ABSTRACT
This chapter explores the following such as to know the component parts of control systems for air conditioning, to know the methods used for water temperature detection, to know how digital communication takes place between computer and control equipment. Automatic control of air conditioning aims to satisfy the temperature and humidity specification throughout the year. Systems of automatic control consist of the principal components: electro-pneumatic transducer, weather compensator, printed circuit card, plug-in module. The standard electrical signal used between detector, controller and computer is 0-10 volt stabilised direct current from a rectifier. The controller has an electronic rectifier to produce a stabilised 10 volt direct current. For direct current and single phase it is single pole and only opens the line conductor. An isolating switch on single phase is double pole. Three-phase wiring has three line conductors and a neutral. Each phase is a different colour. Yellow, blue and red are used.
