Bench Talk

(Source: Phoenix Contact)

As electrical and electronic systems have become increasingly mainstream and automated, there is a trend toward more complex, feature-dense, and "flashy" products in the consumer, commercial, and enterprise automation markets. This trend appears to follow the path of many consumer products that attempt to differentiate themselves from the competition by providing more features, integrations, customizations, and more svelte packaging. This approach may work for some consumers, but it completely alienates many of these products from cost-sensitive applications that don't require additional "frills" and simply need a product that delivers a primary function.

Moreover, feature creep and overengineering are also now more prevalent as purchasing modules and easy integration of a wide range of features become more accessible. Though access to a diverse range of features with relatively simple paths to integrating these modules is attractive, in many cases, adding these additional features and modules isn't enhancing customer or end-user value and is merely increasing costs, time-to-market, and potential failure modes. In many cases, a basic solution that delivers quality performance is all that is needed.

This blog explores a streamlined approach to 24V power supplies for commercial and enterprise automation, focusing on the Phoenix Contact Essential Power line of power supplies, which is ideal for high-volume, cost-sensitive applications.

Power Supply Basic Requirements

A power supply at the most basic level is simply a rectification function that takes AC inputs readily available from grid power systems and converts them to DC functions usable by the control, actuation, and sensing electronics used in automation systems (Figure 1). Many electronic automation systems need clean and reliable 24V power, as 24V is a standard used in industrial automation, and an extensive ecosystem is available for 24V electronics in commercial and enterprise automation. This approach is a cost-effective trade-off to higher voltage systems, providing better noise and interference immunity than 12V systems. Higher voltage systems exhibit less conductive losses than lower voltage systems, allowing for more efficiency. The caveat is that higher voltage systems require more expensive power electronics and more complex design, which generally translates to higher costs.

Figure 1: Block diagram of an essential power supply with indications for the various protection functions and user interface features. (Source: Phoenix Contact)

For commercial and enterprise automation, such as building automation, having a wide range of input voltage capabilities increases the installation flexibility and presents less susceptibility to power grid voltage fluctuations. A power supply that operates between 110V and 240V and between 50Hz and 60Hz can be used in a wide range of markets and is less susceptible to brownouts and input instability.

A wide temperature range is also a sought-after fundamental feature, as these applications may need power supplies located in somewhat harsh building conditions near heating/cooling equipment. Some power supplies can be operated in higher temperature environments, with the expectation that they will likely have a shortened lifespan due to the early degradation of electrolytic capacitors used in the design.

Though many add-ons and extra features can be ignored for basic power supplies, protection features against overvoltage, overcurrent, overtemperature, short circuit, fused input, and transient/surge protection using a metal-oxide varistor (MOV) are non-negotiable. Other necessary environmental performance capabilities for basic power supplies include vibration and shock resistance and the ability to function in a wide range of humidities.

Another crucial consideration for power supplies is compliance with safety standards and regulatory agencies in major markets. Two main standards for commercial and building automation power supplies are being UL listed and IEC 61588-2-16, a safety standard for transformer electronics.

Phoenix Contact Essential Power

The Phoenix Contact Essential Power line of power supplies is uniquely suited to meet the necessary requirements of cost-sensitive commercial applications by providing only what is essential. Where many competing products try to boast the latest features and most advanced technology, this line of power supplies is made to meet and exceed the basic specifications and features needed to deliver quality 24V power for various automation tasks without the feature creep and overengineering that increases costs and integration complexity.

These are all DIN Rail power supplies designed specifically for climate-controlled commercial applications, such as vending machines, test/measurement, solar cell production, printers/scanners, building automation, lighting automation, HVAC, and more. These units are single-phase (1-phase) input devices with an adjustable output voltage from 24V to 28V. Units in this series include 2.5A, 3.125A, 5A, 10A, and 20A versions. Moreover, these devices can be connected in parallel for increased power and redundancy using a protection diode and in series for increased output voltage.

Delivering only the bare necessities, these power supplies comply with IEC 61588-2-16 safety standards and are UL-listed to comply with local electrical codes. These power supplies are highly reliable, operate over a wide temperature range covering virtually all commercial and enterprise applications, and enable flexible installation with a wide input voltage range. There is also a visual operating state display with a single LED indicating the DC voltage is appropriate. Of course, Phoenix Contact Essential Power also features a thorough range of necessary protections for power supplies.

Conclusion

Many electrical and electronic systems designers often tend to include as many features as possible and design a product that far exceeds typical requirements. The now-common level of feature creep and overengineering results in more expensive products that often include erroneous features to the end-user, whereas a well-designed product using minimal features will often do. This is the case with commercial automation power supplies, where many on the market include connectivity, display, and control features that are more than is needed and price-out many cost-sensitive applications. To get back to basics, the Phoenix Contact Essential Power line of power supplies offers straightforward, optimized solutions.

Author

Principal of Information Exchange Services: Jean-Jacques DeLisle
Jean-Jacques (JJ) DeLisle attended the Rochester Institute of Technology, where he graduated with a BS and MS degree in Electrical Engineering. While studying, JJ pursued RF/microwave research, wrote for the university magazine, and was a member of the first improvisational comedy troupe @ RIT. Before completing his degree, JJ contracted as an IC layout and automated test design engineer for Synaptics Inc. After 6 years of original research—developing and characterizing intra-coaxial antennas and wireless sensor technology—JJ left RIT with several submitted technical papers and a US patent.

Further pursuing his career, JJ moved with his wife, Aalyia, to New York City. Here, he took on work as the Technical Engineering Editor for Microwaves & RF magazine. At the magazine, JJ learned how to merge his skills and passion for RF engineering and technical writing.

In the next phase of JJ’s career, he moved on to start his company, RFEMX, seeing a significant need in the industry for technically competent writers and objective industry experts. Progressing with that aim, JJ expanded his company's scope and vision and started Information Exchange Services (IXS).