To ensure electronic components can withstand their end-use environment, purchasers must navigate a host of international standards and certifications. Specialist advice can be invaluable, says Sager Electronics
Although the interpretation of harsh and hazardous conditions can vary, factors such as water, humidity, dust, chemicals, electrical surges, vibrations, electromagnetic interference and temperatures can all cause an electronic component to perform unexpectedly or possibly even to fail.
Clearly, failure is not an option in life-critical designs, so a thorough understanding of the environment where the application will be used and how it will be used is vital. Oil and gas exploration, nuclear power plants, hazardous waste, pharmaceuticals, outdoor environments, industrial facilities and even grain storage are often defined as harsh or hazardous environment industries, but extreme conditions can also be found across a range of more common applications and markets.
Once the criteria for environment and use have been determined, purchasing staff must ensure that the electronic components sourced meet the latest industry certifications and standards for that particular design.
When sourcing life-critical electronic components, key considerations could include: flame proofing, explosion proofing, pressurisation, oil immersion, hermetic sealing, encapsulation, mechanical integrity and intrinsic safety. The first step to ensuring components will operate reliably is to work directly with the manufacturer or through an authorised distributor. Purchasing components from an unqualified source can leave customers exposed to a myriad of potential problems.
Furthermore, by working with an authorised distributor, purchasers have access to the latest technologies and information on standards and certifications. Distributors can, for example, help customers understand relevant standards such as the IP rating used to describe sealing effectiveness for electrical enclosures.
In this rating, the first number relates to protection from solid objects or materials, while the second number relates to protection from liquids. Not used as frequently, the third number denotes protection against mechanical impacts, while an X specifies that there is only one class of protection in that field.
Beyond IP ratings, customers must also take into account a number of other standards such as ATEX, IEC and NEMA certifications. Depending on the type and severity of the expected conditions, purchasers may need to ensure components meet one or more standards issued by different authorising bodies, as well as ensuring that they adhere to any standards required in other countries or regions into which they intend to supply
Reliable supply chain
Several suppliers design products specifically for harsh and hazardous environments. Honeywell, EBM-Papst, Mean Well, BEI / Sensata, Phoenix Contact, Laird and Traco Power are just a few of the suppliers operating in this market.
Bearing in mind the diverse options available, an authorised distributor that works closely with its suppliers will be best positioned to understand the product pipeline from supplier to customer and to react to economic and material influences. As lead times extend and prices increase, distributors that plan their inventory buys and position their backlog with care, particularly in relation to electronic components designed for life-critical environments, can minimise customer impact.
Sourcing off-board power and switch components presents plenty of challenges in an industrial setting, as Sager Electronics’ vice president product marketing, electromechanical, Craig Sanderson, and director of supplier marketing, power products, Paul Kopp, explains
Everyone involved in sourcing electronic components understands the intricacies of sourcing on-board components. Yet off-board components, although they may appear basic, have just as many variables and considerations, especially in industrial applications that require stringent regulatory compliance in potentially harsh environments.
Two key off-board components provide insight into these challenges: switches, which are one of the first components designed in; and power supplies, which are one of the most complex.
Today’s switch offering is more sophisticated than ever before. In addition to turning equipment on or off, switches may require sealing, LED illumination and wireless functionality. These considerations are even more complex when designing-in power supplies. At their most basic, power conversion products change currents or adjust voltage levels, but the variables are many and often a power supply architecture is required.
So, what does purchasing or engineering need to know to source the correct switch or power supply solution? In addition to electrical requirements, there are a few key considerations, not least of which is regulatory and standards compliance.
The regulatory environment has been dynamic over the past several years. Regulatory requirements such as UL, CSA, VDE, CCC as well as environmental standards such as RoHS, REACH, conflict mineral and others all play a role in sourcing the right components. In the power sector, one of the biggest changes occurred in early 2016 when Level VI energy efficiency requirements took effect.
It’s vital that OEMs continually track developments to ensure compliance and avoid costly delays or fines. Working through the distribution channel can ease the burden, since authorized distributors have their finger on the regulatory pulse and have close working relationships with the component manufacturers to help ensure compliance.
Ruggedization is another trend to consider, especially in the industrial sector where demand for robust, harsh-environment ready components has steadily increased. Considerations such as exposure to extreme temperatures, water and humidity, dust, vibrations and physical impact often come into play and it’s not uncommon to require IP67, IP68, or even the most stringent IP69 ratings.
Finally, miniaturization isn’t a new trend, but it continues to be pervasive across all components. Devices now require more power and increased functionality, while also fitting smaller footprints. Off-board components such as switches and power supplies must also meet these expectations.
The most common switches for industrial applications include limit, toggle, push button, oil-tight push button and basic or snap-action. Demand for sealed versions is generally higher in industrial applications, but there are also various other drivers at work in this segment.
Following the miniaturization trend, OEMs are looking for ways to pack more functionality into every component to create the most efficient footprint. Examples of this include circuit breakers used as switches and inline filters packaged together with a fuse and a power switch in a single device.
Physical appearance is another big driver regarding switch design. For example, a panel consisting of multiple switches, indicators, connectors and power supplies requires a uniform size so components fit together as a package. LED technology is also providing aesthetic opportunities, such as lit push button products. Unlike other components, however, switches have relatively few standard configurations and new switch designs are typically driven by specific OEM requirements.
Perhaps the most important consideration when selecting a switch is the degree to which the switch needs to support overall device safety. Some of the most common safety requirements include: heavy duty, high amperage; light duty, high current; harsh conditions and hazardous environments.
Pushing Power Boundaries
Sourcing power supplies is more complex than switches due to the number of variables, requirements and regulations. A lack of standard products and the need for complex solutions make sourcing power supplies a far bigger challenge for both purchasing and engineering.
All industrial electronic devices require power conversion using a power supply. This typically converts one type of electrical power to another, but may also convert a different form of energy such as solar into electrical energy. At the most elementary level, purchasers must first identify the type of power conversion required. For example, is a regulated or unregulated power supply best for the application? Does the application require AC to DC or DC to DC conversion, or does it require an external power supply? From there, the complexity and level of specification greatly increases.
When specifying a power supply, it is also important to understand the basic power requirements including: input voltage, wattage, number of outputs, voltages required, amperage and peak load.
After defining these requirements, there are other variables to consider. Think about the size, efficiency and reliability required. How will heat be managed, for example, and will the power supply be fan-cooled, convection, or conduction cooled? It may also be necessary to consider whether the supply will be used in a wet or damp location.
Other questions might focus on safety concerns, whether interference is an issue, or whether the device requires EMI/RFI filtering. Don’t forget to factor in how long the device will be running and what peak power loads will be required. Engineers must keep up with the latest power regulations and should consider whether the supply requires UL 60950, UL 508, CEC Level VI or UL 8750.
One final consideration in sourcing power supplies for industrial applications is the form factor. There are many different form factor options from open frame to enclosed, as well as encapsulated or PCB mount options. Other applications may call for an external adapter, or a Din rail or rack mount solution.
With so much to consider, a distributor like Sager Electronics and its specialized group, Sager Power Systems, can help by assisting with design, sourcing and supply chain services.
Sager believes the authorized distribution channel is the most efficient way for OEMs to source offboard components. Flexibility, ease of ordering and the ability to achieve economies by sourcing both on-board and off-board components from a single supplier are all hallmarks of distribution. Sager, for example, stocks a broad inventory of interconnect, power and electromechanical products while offering personalized services like bonded inventory programs, vendor managed inventory and bill of materials quotes to meet customer requirements.
As an authorized value-added reseller for its franchised suppliers, Sager also boasts quick turn assembly of modular power supplies. Value-added design and manufacturing services are offered through Sager’s power solutions center in Carrollton, Texas. From simple modifications to complex design, Sager’s team can guide a customer through the entire engineering process, including power supply selection, component sourcing, prototyping, test and manufacture.