Preface: This is the first edition of CSA C22.1CIICHB, Commercial, Industrial, and Institutional Construction Handbook. It is intended to be used as a companion to the 2018 edition of the Canadian Electrical Code, Part I. This Handbook directs the reader to some of the most frequently cited Rules of the Code and other information required by field personnel on a frequent basis. Much of this information is presented in tables that are designed for quick and easy reference. The content is focused towards the commercial, industrial, and institutional construction sector, and includes examples, photos, and calculations. It also provides useful background information related to electrical terminology and procedures. The final sections contain basic tables specifying trade sizes, standard ratings, and equivalents, followed by excerpts from the most commonly consulted Code Tables and Diagrams. This Handbook is designed to be a quick and portable reference guide in the field. Since the material is not intended to be complete, the Commercial, Industrial and Institutional Construction Handbook is not under any circumstances to be used in place of the Canadian Electrical Code, Part I. CSA Group does not assume responsibility for any errors or omissions resulting from the information in this Handbook. The Handbook is organized by topic with a table of contents at the beginning. Starting out with metric units and formulas, continuing to fuses and circuit breakers. Motors and transformers are then discussed in detail with examples and calculations. At the end is a list and pictures of the top ten defects found in Ontario, commonly asked questions, general information tables as well as excerpts from Tables in the Canadian Electrical Code.