Proper grounding of electrical systems is critical for personnel safety, equipment protection, lightning protection, and error-free analog and digital signal transmission, yet it is probably the most misunderstood area of electrical design.
Most electrical designers are comfortable with grounding of 60-Hz power systems for safety and fault protection, but they may find themselves challenged when confronted with grounding for instrumentation, communication, surge protection, or data processing facilities; at the higher frequencies involved, these ground systems do not behave according to simple circuit theory like the familiar 60-Hz systems, leaving many designers without the tools to fully understand their performance. As a result, trial-and-error solutions prevail, and grounding receives a reputation as a "black magic" art that cannot be understood by the uninitiated.