Tough enclosures simplify remote I/O installations

Jon Lawson

Intertec has launched a range of tough field enclosures for housing remote I/O and other control and instrumentation electronics, featuring compact passive cooling to dramatically reduce costs of ownership. The new enclosures help process plant engineers to eliminate the need for large and costly plant buildings such as satellite instrument houses or remote instrument enclosures – which often need to be air conditioned and blast- and fire-resistant.

Fabricated from GRP (glassfibre reinforced polyester) materials, the enclosures provide rugged dust- and water-proof environments to protect remote control equipment located deep inside processing areas. The enclosure concept simplifies the roll-out of more versatile distributed control architectures containing field equipment. The advance can allow field control equipment enclosures to be assembled and sealed in the factory – an efficient and cost effective process – avoiding the need for opening and exposure to dangerous local conditions at the site during installation and operation.

The ability of the enclosures to be fabricated with embedded insulation (a monolithic sandwich with layers of GRP sheet enclosing insulation) is a major virtue. Insulation is commonly required because modern remote I/O applications use sensitive electronic devices, with lifetimes and reliabilities that are drastically reduced by overheating.

Efficient insulation helps protect against temperature extremes. This is one reason why the simple steel cabinets widely used for cabling-related field junction boxes are not adequate for some of the more sophisticated remote I/O applications now being deployed.

Because of the electronic devices used, some form of cooling may also be required. If power is available at site, this can be in the form of conventional fan cooling. However, the temperature stability of highly insulated GRP boxes makes it possible to efficiently exploit passive cooling techniques which require no electricity and have no moving parts – also making them suitable for deployment in hazardous areas.