Enclosures

To protect and serve” appears on countless police and public safety vehicles in the United States. Although taken for granted by many, it is a serious motto for those in law enforcement, fire protection, and security fields. This same motto could appear on industrial enclosures as well. Their function is also to protect and serve.

02/01/2007


System integration

Most enclosures are purchased for in-plant applications.

Although protection varies with the item (workstations, PLCs, DCSs, instrumentation, HMIs), respondents listed the following attributes as necessary when specifying an enclosure (in descending order): dustproof, waterproof, wash-down resistance, A/C cooling capability, EMI/RFI shielding, office-level/non-hardened capabilities, explosion-proof, heating capability, and UV protection. Dustproof, waterproof, wash-down resistance, cooling, and EMI/RFI resistance were invariably tagged for typical in-plant uses. Non-hardened enclosures were most used in standard computer/workstation applications.

Applications were further broken down by enclosure environments/location. The majority found their way to the plant floor, which included sanitary/wash-down and hazardous/dusty environments. Less than half that amount were used in an office environment and a small number (less than 2%) ended up out-of-doors.

Respondents chose availability from stock and cost as the most important factors when selecting enclosure suppliers. Other criteria affecting choice includes ease of use, the ability to customize (for example, add cutouts, colors, rack, rack locations), modular design, and the availability of technical support. The only change in the listing from previous surveys (and eclipsing tech support for the first time) was an increased preference for modular enclosure design.

Enclosures

Leading applications for enclosure use, survey respondents, said, were SCADA (48%); machine control and CNC equipment (40%); and motion control and robotics (38%).

A modular enclosure system is designed to be flexible and easy to expand in capabilities or size. According to Troy Miesee, industrial business and product development manager at Rittal Corp., “With more and more companies providing to the global market, it has become important to be able to adapt a standard design, whether it be an enclosure or a complete system, to the application or requested need. These designs can easily have accessories such as shelves, brackets, and mounting panels added, as well as the ability to bay multiple enclosures together to increase the size of the system.”

Modularity allows designers and builders to configure and build various systems from a standard platform, which can reduce engineering and assembly time and enclosure inventory. Bill Geese, product manager for CCS-Inc. suggests another reasons for the rise in the popularity of modularity: “In most production-floor system rollouts, the enclosure is seen by the customer as the component with the least risk. For this reason, the selection of an enclosure system is not attended to until late in the project, when the requirements are fully understood. By then the project schedule does not allow for customization in the traditional sense, so customers turn to enclosure lines that support customization through modularity,” he says.

The survey says the greatest percentage of enclosures are specified in carbon steel or stainless steel. These materials shared the lead in earlier surveys. Most recently, aluminum enclosures took over third place from fiberglass/engineered plastic for the first time.

Lighten up with aluminum

Any number of applications require the rigidity, strength, and fire-resistance of steel enclosures. Although stainless steel can provide the corrosion protection that carbon steel cannot, both are heavy and may be ill-suited to an application when larger size, mobility, or ease of installation are required. Aluminum offers lightweight construction (similar to both fiberglass and engineered plastics), with many of the benefits of steel.

System integration

Compared to two years ago, respondents to this survey showed increased use of stainless steel and aluminum.

The high cost of stainless steel and fiberglass/ plastics has also made aluminum more attractive. Rittal’s Miesse says his company has seen an increase in requests for aluminum. “However, Rittal sees this only as a next best alternative to stainless and fiberglass when price is a major issue,” he adds.

CCS-Inc.’s Geese adds that the rising cost of petroleum products present in most, if not all, non-metallic solutions may also be partly to blame. “Couple this with the fact that it is very difficult and costly to do true customization in non-metallic solutions, and one can easily accept that aluminum has become more popular than non-metallic enclosures,” he adds.

For enclosures used indoors, this survey asked about respondents’ familiarity with RoHS (Restriction of Hazardous Substances) requirements affecting enclosures and consoles. Most (>90%) said they were not very familiar or not familiar at all with them. According to Ron Rotondo, product manager for Hoffman, RoHS relates to enclosure construction materials, specifically to corrosion-resistant plating (hexavalent chromium, for instance) and nonmetallic materials (some compounds in fiberglass materials). RoHS regulations restrict the use of some substances in manufacturing to try to prevent hazardouns material from leaching into the environment.

Environmental concerns

When properly disposed of, RoHS-compliant enclosures have limited environmental impact. The legislative environment around RoHS is changing. The European Union RoHS Directive took effect July 1, 2006. China and California are both considering similar directives. Users’ knowledge varies with business environments. Machine builders that export to Europe have already been impacted. Additional legislation will force everyone to become familiar with such regulations. Rotondo points outs that Hoffman’s online catalog marks compliant products with a RoHS emblem. “Currently, we are 92% compliant for all products. Additionally, customers will be able to request and download RoHS compliance certificates to build their technical file through our Website in early 2007,” he adds.

Users may take enclosure capabilities for granted because most products have met changing market needs seamlessly, living up to the motto: protect and serve .

Enclosure products

For more manufacturers, visit www.controleng.com/buyersguide . For systems integrators, visit www.controleng.integrators . Also visit company Websites listed.


 


Enclosure air conditioners

Type 4 Indoor/Outdoor T4 air conditioners from Hoffman provide high-efficiency positive cooling for wall-mount and free-standing enclosures. The line is said to offer an increased range of protective capabilities and more BTUs of cooling to protect electronic controls and equipment from potential failure from excessive heat inside a sealed enclosure. Six models vary in footprints and capacities. www.hoffmanonline.com

Hoffman

Enclosures

System integration


Protected enclosures

Pushbutton enclosures from Rittal include heavy-duty carbon steel and stainless steel models. Designed with continuously welded, smooth finished seams, and constructed of 14-gauge carbon steel for strength and durability, they feature an interior and exterior polyester-urethane powder coated finish over a phosphatized surface to enhance corrosion resistance. UL and CL listed, these are rated UL Type 4, 4X, 12 and 13. www.rittal-corp.com


Enclosures with window

NEMA 12, 4 enclosures from Hammond Mfg. enclose electrical and electronic equipment in wall-mount applications and allow viewing while maintaining many protection ratings. They have hidden hinges, attractive latching systems, and a range of sizes and accessories. www.hammfg.com

Hammond Mfg. Ltd


Spray-down protection

SN Series NEMA-rated sheet metal boxes from Bud Industries offer economical spray-down protection—often at less cost than previously available drip-protected enclosures. They feature continuously welded seams and a hinged cover that clamps to the base with stainless steel screws and brackets for a water-tight seal. Manufactured from 14-gauge steel and finished in gray powder coating, the boxes are rugged and mar resistant and come with a 14-gauge steel, powder-coated removable inner panel. SN Series meets NEMA 1, 2, 4, 4X, 12, 13, and IP65 ratings. www.budind.com

Bud Industries Inc.

Enclosures


Protection from contaminants
N412C Ultimate Series enclosures from Hubbell Wiegmann are designed to house and protect electrical and electronic components from harsh, dirty environments. For use where dirt, dust, oil, water, or other contaminants are present, these enclosures feature streamlined styling, flush latching, and attractive durable finish. Unit has a single door, mounts on the wall, and is rated UL508, Types 4, 12, & 13; CSA Certified, Types 4, 12, & 13; NEMA/EEMAC Type 4, 12, & 13; and JIC EL-1-71.
Hubbell Wiegmann


Designed for flexibility

H- and J-frame PowerPact molded case circuit breakers are the first enclosures designed specifically for Square D that provide increased flexibility for commercial and industrial applications, says the developer, Schneider Square D. Allowing for easy installation of breakers and internally mounted accessories and lug provisions, the enclosures give contractors and facility managers more options for 15-250A applications where a branch circuit disconnect with circuit protection is required. Among the five new enclosures are a NEMA Type 12-rated gasketed, dust-tight version, and a stainless steel NEMA Type 4 water- and Type 4X corrosion-resistant model.
Schneider Square D

System integration

Schneider Square D offers H- and J-frame PowerPact molded case circuit breakers.

Slope-top workstation enclosures
Units from Saginaw Control & Engineering are intended for indoor or outdoor NEMA 12, 4, and 4X applications. Design incorporates a 20° sloped top to prevent unwanted debris or liquids from pooling or collecting in a wet or wash down environment. A 12.5° sloped keyboard desk provides a comfortable ergonomic work surface.
Saginaw Control & Engineering

Double deep fiberglass enclosures
Fatboy double deep J Series fiberglass enclosures from Stahlin feature a clam-shell appearance and the durability necessary to provide “extra space” without adding height or weight. The enclosures are suited for indoor and outdoor environments. All are UL/CSA rated to Type 12, 3R, and 4X and IEC 60529 IP66 for protection against environmental extremes. Fatboy’s lightweight, durable, one-piece construction requires no collar attachment and saves time and labor when modifications (holes, cutouts and vents) are required. Formulated from Stahlin’s proprietary fiberglass material that ensures UV resistance, the enclosures also feature stainless steel latches and hinges, urethane gasketing for a reliable seal, back panel mounts in the cover and base, and an integral mounting flange.
Stahlin Non-Metallic Enclosures

Enclosures

Strongarm operator interface enclosures have many design variations.

 

 

Operator interface enclosures
Operator interface enclosures require special considerations says manufacturer Strongarm. Smaller size reduces intrusion to the operator area. It also checks clearances for cable connections and heeds CD drive doors, airflow, and other design considerations while reducing overall enclosure volume. Options and accessories include pendant arm mountings, keyboards and pointers, coolers, side access doors, external ports and special finishes. Each enclosure is shipped assembled, tested, and ready to install.
Strongarm


For difficult washdowns

ID42 enclosure from ITSEnclosures is intended for harsh and difficult washdown environments. Unit provides protection for a PC and up to a 21-in. display and keyboard. It features an adjustable shelf for maximum flexibility when positioning electronics, and a dual-level retractable keyboard drawer/work surface that provides ergonomic access and added protection for a keyboard and mouse. Lockable doors and keyboard drawer enhance security. Enclosure is built to NEMA 4X standards; its sloped top prevents moisture collection.
ITSEnclosures Inc.

 

System integration

ID42 enclosure from ITSEnclosures works in tough environments.

Enclosures

MNX enclosures from Fibox USA resist corrosion.

 

 

Corrosion-resistant enclosures
MNX enclosures from Fibox USA protect electronic components operating in harsh environments. Corrosion-resistant enclosures, made from polycarbonate and ABS, feature three body and five cover depths to offer more than 240 variations, reportedly one of the most comprehensive product lines in the industry. Custom molds are available for high volume applications. Features include solid or transparent covers, a continuous gasket molded in place on the cover that ensures a waterproof fit, and an optional swing-out interior panel. Cover has a recessed center to protect membrane keyboards or printed graphic overlays. Internal mounting pods offer three depth options for mounting internal components such as DIN rails and printed circuit boards. Sizes range from 3.9 x 3.9 x 10.0 in. to 7.1 x 1.4 x 6.9 in. Accessories include mounting plates, hinge sets, inner swing-out panels, wall mounting brackets, and DIN rails. Polycarbonate enclosures are available with built-in, cable entry knockouts. MNX enclosures are rated NEMA 4X and are UL listed. All comply with RoHS regulations.
Fibox USA

Enclosure heat exchangers
Air-to-air heat exchangers from Noren remove waste heat from electronics to achive temperatures slightly above outside ambient, maintaining NEMA 12 integrity or better. With added protection, units may be made splash proof and corrosion proof, either NEMA 4 or 4X (stainless steel). Noren Cabinet Cooler is said to be 1/6 the size, 1/7 the weight, 1/10 the energy, 1/5 the cost of conventional air conventional and is Freon-free and said to work 13 times longer.
Noren Products Inc.

Enclosures for PC boards
BOS-Ecoline enclosure system from Rose+Bopla combines custom sizing advantages with cost-effective ABS plastic end caps to create a robust enclosure for many electronic applications. Clear anodized aluminum profiles are available in three versions: closed, open on one side, or split profiles, and in four profile widths with integral guide grooves for PC Boards.
Rose+Bopla

Other recently introduced products, from companies not named in survey results, include the following.

Reinforced polyester enclosures

System integration

Ultraline enclosures from Allied Moulded Products include industry exclusive mounting options, company says.

New Ultraline NEMA 4X electrical or electronic, fiberglass reinforced polyester enclosures from Allied Moulded Products comes standard with what are said to be industry exclusive mounting options, including an out-of-the-box mounting flange or adjustable mounting feet to cover various configurations. Ultraline also features molded latch keepers, a tongue-and-groove seal design, and a flange design. A clear polycarbonate cover option is available for instrumentation applications where critical electronic equipment must be visible and protected from the elements.
Allied Moulded Products Inc.

NEMA-rated enclosed workstations
TecStation Xtreme is part of CCS’ line of NEMA-rated enclosed workstations. It allows companies to safely put computers in hazardous manufacturing and production environments where flammable gases and vapors are present. Stainless steel enclosure meets NEMA 4/4X requirements and is suitable for Class I, Div. I and II locations. Product uses instrument quality compressed air or inert gas in its purge system to maintain a slightly higher internal pressure and prevent flammable gases from entering the enclosure. Pressure is regulated, 60-115 psi, and it can function at 4-131 °F. Other features include self-sealing doors with lift-off hinges, a monitor viewing window, and keyed compression latches. Enclosure accommodates desktop LCDs (up to 21-in.) and small form factor PCs in pedestal or benchtop models.
CCS-Inc.

Transport, cool electronics safely
Air conditioned transit cases from EIC Solutions Inc. are designed to safely transport, protect, and cool electronics. A built-in thermoelectric air conditioner provides the cooling needed to maintain safe temperatures within the cases for instruments, computers, telecommunications equipment, terminals, surveillance devices, and other specialty electronics in the harshest environments. The design combines a thermoelectric air conditioner with a durable, stackable, lightweight, portable transit case, suitable for use in various industrial, military, and defense applications. The impact- and corrosion-resistant cases are available in various sizes, colors, and types, including 19-in. rack-mount styles, clamshell designs, and custom configurations. Built-in 200, 400, 800, or 1500 BTU thermoelectric air conditioners are available in NEMA 12 or 4X configurations for indoor or outdoor use. Optional equipment available for the cases includes cable exit ports, locking latches, casters, shelves, insulation, RF/EMI protection, desiccant material, and custom colors.
EIC Solutions Inc.

Enclosures

Enclosures Direct (EDI) says it has 3,000 standard enclosures in its wall mountable line.

Enclosure services beyond standard items

Product and service options from UL- and CSA-approved manufacturer Enclosures Direct (EDI) include standard NEMA electrical and electronic enclosures in stainless steel or powder coated mild steel powder said to compete with the industry’s larger, global enclosure manufacturers. Product flexibility and unique service options include more sizes to choose from (3,000 standard enclosures in its wall mountable line), no minimum order size, quick turnaround (days rather than weeks) on modifications, and better pricing. EDI enclosures are manufactured on a just-in-time basis using robotic welding and metal finishing. Options include foam-in-place gaskets, a patented hinge for improved waterproofing, powder coated finishes, and small or large order modifications (hole punching, special weld studs, paint colors). All secondary operations are all done in-house.
Enclosures Direct

30.5 mm pushbutton enclosures

System integration

Allen-Bradley 800H pushbutton yellow plastic enclosures from Rockwell Automation increase visibility for 30.5 mm pushbuttons.

Global OEMs and manufacturers who require increased visibility of push button stations for e-stop applications will like the new yellow Allen-Bradley 800H pushbutton plastic enclosures from Rockwell Automation. The yellow 30.5 mm pushbutton plastic enclosures add to a line of definite-purpose style enclosures. The bright color is designed for applications requiring e-stop with a yellow background or applications requiring increased visibility of the push button station. The UL and CSA rated enclosures are lightweight and high-impact resistant. Increased flexibility is available with 1-4 hole configurations, and cover-to-base orientation makes it convenient for customers to correctly select and install.
Rockwell Automation

To protect and serve” appears on countless police and public safety vehicles in the United States. Although taken for granted by many, it is a serious motto for those in law enforcement, fire protection, and security fields. This same motto could appear on industrial enclosures as well. Their function is also to protect and serve. It is a job taken very seriously by enclosure manufacturers: providing users with a way to protect electrical and control components from a variety of problems, including environmental contaminants, moisture, temperature changes, shock/physical damage, and tampering. Enclosures also serve as a terminus and/or mounting site for electronic or control devices and their wiring.

The right protection

According to a recent on-line survey by Reed Research Group and Control Engineering magazine, enclosures are widely applied. The majority (51%) are used for in-plant requirements , with 30% used for OEM (resale) requirements. The remaining 19% were bought for both in-plant and OEM uses.

Primary applications vary widely (see accompanying graphic). Responses put supervisory control and data acquisition (SCADA) applications at the top of the list, followed closely by machine control/CNC and motion control/robotics applications, which are common (almost generic) in discrete manufacturing operations. Continuous and combined continuous/batch processes also account for a large share of the applications, coming in fourth and seventh in the list of uses. Compared to a year earlier in 2005, most applications remained in essentially the same or close to the same order.


Author Information

Dick Johnson is a consulting editor with Control Engineering. He can be reached at djtheme2003@aol.com .