Enclosures for all seasons

Protecting electric installations from the weather and other hazards

By Morand Fachot

Safeguarding outdoor electric installations from the weather and other potential environmental or accidental hazards is essential for their proper operation and for safety. Outdoor enclosures, unobtrusive and frequently overlooked by the general public, are central to this protection. Preparing International Standards for stationary outdoor enclosures is the responsibility of IEC SC (Subcommittee) 48D: Mechanical structures for electronic equipment.

Outdoor enclosure near a beach Outdoor enclosure near a beach

CDVs (committee drafts for vote) for the three separate parts of the forthcoming second edition of the IEC 61969 series of standards, Mechanical structures for electronic equipment – Outdoor enclosures, were approved recently. They concern the following: design guidelines (Part 1), coordination dimensions (Part 2) and environmental requirements, tests and safety aspects (Part 3).

Modular design

Outdoor enclosures are meant to contain and protect a wide range of installations against environmental impacts. These may include communication systems and industrial and signal controls. These enclosures must be designed to house equipment fitted in sub-racks of certain dimensions as well as cabling and possibly power supplies, batteries or cooling/heating devices. Therefore, they must also comply with existing relevant standards for the above-mentioned.

All-round protection

Outdoor enclosures can be installed in a variety of ways. They can be wall-mounted or installed on top of a building, fitted to a pole or free-standing on the ground. As such, they must also meet a number of different conditions to protect them from the impact of the weather (sun, rain, heat, cold, humidity, etc.) and of various corrosive substances (dust, gases and liquids).

Freestanding enclosures, for their part, may be subjected to vandalism or face physical impact and must be designed accordingly. In particular, enclosures installed near roads may require additional protective measures from possible contact with vehicles.

Not merely a plain box…

Albeit very inconspicuous, outdoor enclosures are pervasive in the modern environment. Considering all the requirements they must meet and the devices they incorporate, they are not just simple grey unremarkable boxes but carefully-designed pieces of equipment and vital parts of a larger puzzle in which the IEC's work can be found at all levels.

Outdoor enclosure sheltering signal equipment Outdoor enclosure sheltering signal equipment
Outdoor enclosure near a beach Outdoor enclosure near a beach
Standalone enclosure Standalone enclosure