Guide for Instrumentation and Control Equipment Grounding in Generating Stations
|Publication Date:||24 September 2004|
This application guide was developed to identify instrumentation and control (I&C) equipment grounding methods to achieve both a suitable level of protection for personnel and equipment, and suitable electric noise immunity for signal ground references in generating stations. Both ideal theoretical methods and accepted practices in the electric utility industry are presented.
This guide is intended to give information on grounding methods for generating station instrumentation and control equipment. Grounding design is normally based on the concept of two separate grounding systems, the equipment ground and the signal reference ground. The concepts of equipment grounding are well covered in other IEEE standards. The concepts of grounding of instrument chassis, cable shields, signal pairs, and other related instrumentation and control items require special care in order to ensure that both personnel working on equipment are adequately protected from electrical shock and that interference signals are not inadvertently coupled into signal circuits. Although safety takes top priority, the I&C systems must be simultaneously safe and operationally reliable.
The basic theory and guidelines that should be understood before designing I&C grounding are presented in Clause 4. Clause 5 presents various approaches for the grounding of equipment associated with generating station I&C systems. Clause 6 presents accepted practices in grounding the shields of I&C cables, while Clause 7 covers the testing of I&C grounding systems.