Enclosures: The First and Often Only Line of Defense
Protecting delicate controls, electronics, and wiring from acrid industrial environments and the occasional out-of-control forklift is no easy task. However, it is easier in some places than in others. Not all enclosures specified by control engineers end up enduring industrial hazards. Of the 211 respondents to Control Engineering's recently e-mailed research questionnaire, many had less dem...
Protecting delicate controls, electronics, and wiring from acrid industrial environments and the occasional out-of-control forklift is no easy task. However, it is easier in some places than in others. Not all enclosures specified by control engineers end up enduring industrial hazards. Of the 211 respondents to Control Engineering's recently e-mailed research questionnaire, many had less demanding duty in mind.
The survey by Control Engineering and Reed Research (Newton, MA) looked at a wide variety of topics of interest to enclosure specifiers. Questionnaire topics included:
Primary applications for enclosure use
Types of protection specified
Types of cooling specified
Principal areas of application
Levels of protection specified
Types of materials specified
Current and future purchasing plans.
Results of the online survey showed that the majority (79%) of those responding were directly involved in specifying, recommending, and/or buying enclosures. Of these respondents, 48% were involved in specifying enclosures for in-plant requirements, 21% for OEM (resale) requirements, with the remainder making buying decisions for both in-plant and OEM requirements.
Who is using them where?
Of those applications destined for direct use by the control engineer, the greatest majority will see duty on the plant floor (as the graphic shows). These applications are generally considered benign. However, exposure to dust, dirt, vibration, heat, cold, EMI/RFI, natural disasters, and physical abuse are all possible in ordinary in-plant environments. Additionally, security and resistance to tampering and vandalism are frequently considered when an enclosure is specified.
Hazardous-duty environments remain among the more specific uses for enclosures.
According to Bill Southard, president of DST Controls (Benicia, CA), ''It used to be that Class I, Div. 1 (or 2) meant putting a size 0 motor starter in a 300-lb enclosure that looked like it was made in the former Soviet Union.
''Today, thanks to National Fire Protection Association standards and Z-Purge capability, these same enclosures can be smaller, lighter, and much less costly. There are still areas in a few industries that require explosion-proof enclosures, but most integrators today will try to use a purged enclosure in the classified area.''
Not so tough duty
According to the survey, almost as many enclosures find their way into office environments as hazardous duty or sanitary/washdown environments. Function of these enclosures cannot be overlooked. Office environment applications of enclosures include heating, ventilation, and air-conditioning, behind-the-walls accommodation of electrical terminations, server room electronics containment, protection of modems, remote environmental monitoring devices, and utility services. Other non-factory, but not strictly ''office,'' environment applications for enclosures can include marine/dockside uses, commercial construction/equipment, underground tunnel services, and analysis labs.
According to Mike Jackson, engineering manager at Stahlin Non-Metallic Enclosures (Belding, MI), ''Non-factory users of enclosures have been a leader in the specification of thermoset fiberglass enclosures. Non-factory applications have been a key driver for manufacturers of non-metallic enclosures to develop new enclosure products and accessories. Because the public more often views these products, designers are more apt to look at the enclosure design and material as an integral part of the overall product design/function compared to enclosures for factory use.''
Enclosures are ubiquitous and the need to correctly specify them is an absolutely necessary in the control engineering design process. With today's expanded enclosure offerings, preparing this first line of defense for control equipment has been made simpler and more convenient.
-Control Engineering Staff
Comments? E-mail MHoske@cfemedia.com
For more manufacturers of these products, visit the Control Engineering Buyer's Guide at www.controleng.com/buyersguide .
Enclosures maintain washdown environments
Anoka, MN - Watershed Enclosures are a line of stainless-steel freestanding and wall-mount units with features designed to help prevent accumulation of contaminants by eliminating areas where water can pool. They are certified by NSF International, which is reported to be the world leader in standards development and product certification for public health and safety. Features include a unique 20° sloped top, lift-off doors, sloped top and bottom to promote runoff, contoured latching, and bullet hinges that minimize entrapment. A slanted flange trough collar prevents water from pooling along the top edge of the enclosure opening. The UL 4X-rated Watershed line includes 36 new models. www.hoffmanonline.com
Hoffman Enclosures Inc.
Top-mount air conditioning
Springfield, OH - TopTherm top-mount enclosure air conditioners prevent damage to modern cabinet-mounted electronics from heat and dust. Features include an attractive grille, master slave control, door interlock, remote diagnostics, optimized air routing, and two controller versions. Air conditioners optimize cold-air circulation in the enclosure by removing warm air in the center, and then introducing cold air with up to four outlets arranged at corners of the cabinet. Air intake is at the front of the air conditioners, while warm air exhausts are at the sides and to the rear of the unit. TopMount provides useful cooling output from 1,000 to 13,600 BTUs.
UL/NEMA 12 cabinet racks
Cleveland, OH - Bud Industries now supplies two cabinet racks that comply with NEMA 12 and IEC 529 IP55 requirements. The cabinets have been tested and listed under UL-508 12 for use in the U.S. and Canada. The cabinets are intended for applications where electronic equipment must be protected from dirt, dust, and dampness. They are equipped with oil-resistant gaskets, for additional protection.
Offered in two sizes, NR-10025 has internal panel space dimensions of 19 x 70 in., with a usable depth of 29.25 in. NR-10026 features panel pace dimensions of 19 x 78.75 in. with a usable depth of 29.25, 19, or 23 in.
Bud Industries Inc.
Panel management system
Belding, MI - DiamondShield is a family of high-quality, cost-effective fiberglass enclosures. Through its 'No Limits' Panel Management System, a panel of any size can be mounted at any height or depth and hinged in any direction (even on the door), allowing use of all available space to fit more into less. DiamondShield is available in 10 sizes from 6 x 6 x 4 in. to 20 x 16 x 10 in., with more than 150 configurations. Enclosures meet all applicable IEC, NEMA, UL, and CSA ratings to NEMA 4X, IP66.
Stahlin Non-Metallic Enclosures
Aurora, IL - The ''Heavy Duty'' line of electronics cabinets can hold up to 3,000 lb of equipment, comes in four depths, three panel widths, and 37 panel heights, up to 84 in. For shock and vibration, the enclosures qualify under Mil-Std 810D, section 513.4, and Mil-Std 901. For earthquake resistance, reinforcing can be added to meet testing through the most severe Zone 4. Protection from dust, moisture, and EMI/RFI are also available. Custom modifications and colors are available.
Equipto Electronics Corp.
Wall-mount line expanded
Norcross, GA - The SN line of wall-mount enclosures now features over 100 standard stock sizes. Single- and double-door enclosures feature foamed-in-place gasketing, 180° metal hinges, reversible doors, 8-mm tamper resistant locks, and pregasketed cable entry plates, which are removable from the inside only. Other features include ground studs with hardware on door and enclosure body, galvanized mounting plates for superior grounding and shielding, and weather-resistant, epoxy-polyester, powder-coated finish. All enclosures carry UL, CSA, GL, and Lloyds Register of Shipping approvals.
Enclosures feature function and style
Concordville, PA - Model OD45 enclosure line features functional, handheld, and smaller-sized electronic enclosures. The plastic enclosures are constructed of UV stable 94V-2 polycarbonate and are waterproof. The enclosures are said to be rugged and attractive. They withstand harsh outdoor environments and are suitable for clean-in-place applications. These NEMA-4X/IP56 enclosures are intended for a wide range of applications, including outdoor communications units, lighting controls, test equipment, remote flow monitors, and pump controls.
Protect your printer
Mt. Pleasant, PA - The Bar Code Printer Enclosure has been designed to accommodate and protect a wide variety of standard bar-code printers. The enclosure contains access for single front door locking to maintain equipment security. A media slot is integrated into the front door for easy access to printed media. The unit also includes a rear-split panel, which permits quick cable access and management. Additionally, a built-in sliding shelf allows easy access to all sides of the printer for loading of new media. It has a NEMA 12 rating.
Warminster, PA - FRE and FSE enclosures are rugged, freestanding, mobile units that protect computers and other sensitive electronic equipment from dust, temperature, moisture, corrosion, and vibration.
All models are upgradeable. Custom modified, thermoelectric cooling systems from 400 to 1,500 BTU/hr, NEMA 12 and 4X, and hazardous-location configurations are also available.
EIC Solutions Inc.
Expanded enclosure line
Syracuse, NY - Cooper Crouse-Hinds has announced a major addition to its existing line of cast and fiberglass reinforced polyester industrial electrical enclosures. The new enclosures are intended for hazardous and ordinary locations, as well as for application-specific customers, such as OEMs, engineers, and product specifiers requiring worldwide approval.
Easy to install and maintain, these enclosures are available in steel, stainless steel, die-cast aluminum, copper-free aluminum, polyester Krydon, fiberglass-reinforced polyester, and gray iron.
Glen Burnie, MD - Fibox has introduced an enclosure ventilation device (sold in pairs), featuring a molded-in-place gasket that ensures a tight seal and eliminates the loose, separate gasket required in older models. Without a design change, users can now select an easier-to-install, cost-saving assembly with the same mounting-hole pattern and footprint as in previous models. This ventilation device can be used with all Fibox and other manufacturers' enclosures, metallic and non-metallic. A compatible fan holder is available for applications where forced air transfer is required.
OIT mounting packages
Horsham, PA - Operator-interface (OIT) mounting packages are reportedly complete in every detail. Customized from off-the shelf StrongArm products, OEMs can specify exact modifications, additions, and finish. A typical package starts with the company's Vertica Pendant arm that provides vertical adjustment and a perfectly sized enclosure for the OEM's operator interface terminal. The packages are available in NEMA 4 and 4X.
StrongArm Designs Inc.