Power and Grounding for Audio and Audio/Video Systems

By Jim Brown

Jim Brown presents a collection of good engineering practices that is both safe and effective that surround power and grounding for audio and video systems.

A White Paper for the Real World

Considerable confusion seems to surround power and grounding for audio and audio/video
systems. This “White Paper” is an attempt to cut through the confusion and set out a col-
lection of good engineering practice that is both safe and effective. The author believes that the recommendations and practices outlined herein are safe, and that they conform to building codes in most of North America. The author is an electrical engineer by training and an audio systems consultant by profession, but is not a registered Professional Engineer. No warranty is made or implied as to the extent to which these practices conform to local codes or regulations. Qualified professional engineers and electrical contractors should design and install all electrical systems.

AUDIO AND VIDEO SYSTEM POWER REQUIREMENTS

With the exception of a few very large power amplifiers and video projectors, virtually all audio and video equipment sold in North America utilizes single-phase 60 Hz power at 120V. Few individual pieces of equipment require more than 20A; most require far less current. The largest projectors and amplifiers may require 240V, 60 Hz, single phase power, at up to 20A.

Most audio and video equipment draws relatively little power. Audio and video equipment
falls into two basic categories – small signal equipment and large signal equipment.

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