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Canadian Electrical Code 2018 - New Requirements for Intrinsically Safe System Documentation

March 19, 2019


The 2018 edition of the Canadian Electrical Code was published in January 2018 and came into force in Alberta on February 1, 2019. In this blog post, changes to the code related to Intrinsically Safe (IS) system documentation will be discussed.

Section 18 of the Code applies to hazardous locations and the requirements for electrical equipment and wirings that are installed in these areas. The most recent edition of Canadian Electrical Code introduces a new terminology in rule 18-002, named “Descriptive System Document”.

What is a Descriptive System Document?

Based on the Code definition, Descriptive System Document is a document in which the items of electrical apparatus, their electrical parameters, and those of the interconnecting wiring are specified.

Rule 18-064 1) stipulates the new requirement for IS system documentation:

“Rule 18-064 1): Where an intrinsically safe electrical system or non incendive field wiring circuit is installed in a hazardous location, a descriptive system document shall be provided.”

How does an Intrinsically Safe (IS) system work?

Intrinsically safe electrical systems are designed to limit the maximum of electrical and thermal energy in a circuit to a level below what is required to ignite an explosive gas or dust atmosphere.

Analysis, Evaluation and Documentation

Technically, the design of intrinsically safe circuits is categorized into one of the following two methods:

a) Circuits for which the manufacturer designs and markets the intrinsically safe field device(s), the associated equipment, and the interconnecting wiring as a complete system; and any change in the devices or replacements must be done based on the original certificate. Otherwise, the system doesn’t maintain CSA requirements, or

b) Circuits for which the designers select an intrinsically safe field device(s) and match its electrical parameters (commonly known as entity parameters) to the associated equipment and the interconnecting wiring.

All aspects of certification, area classification, and entity parameters for the intrinsically safe or non-incendive circuits, are evaluated, addressed and documented in the Descriptive System Document.

All Descriptive System Documents and supporting calculations should be traceable to a registered professional engineer working under a permit to practice, or the system should be certified by an accredited certification organization as required by the Code and Provincial Authorities.

The Descriptive System Document is intended to facilitate the safe installation, verification, and maintenance of the intrinsically safe electrical system.

Reference: C22.1-18, Canadian Electrical Code, Part I

Autopro Can Help

As an engineering company, Autopro is able to assess maintaining the CSA requirements, design and engineer Descriptive System Documents for the intrinsically safe systems in existing and new facilities based on the Code requirements and clients specifications, and support the full scope of clients requirements through inspections, maintenance and upgrading the intrinsic safe systems.

For more information on this and our other services, please contact us: