Industrial Control Panels: Key Design Insights

(Source: Eakrin/stock.adobe.com)

By Hector Barresi for Mouser Electronics

Published January 22, 2026

My career has revolved around industrial automation and control, meaning I've been dealing with control panels since I was 18 years old. Back then, I was in chemical factories, working on control panels for maintenance and calibration. These panels have been a constant presence in the industry, serving as essential components of any control room or control environment.

In this article, we walk through how industrial control panels function, how they have evolved, and the standards and practical challenges that continue to shape their development.

The Primary Role of Control Panels in Industrial Settings

Control panels can be thought of as the skull for an industrial plant—they house and protect the “brain” of the factory. Everything that happens in a refinery, chemical plant, or power station is controlled by systems like programmable logic controllers (PLCs), remote terminal units (RTUs), or distributed control systems (DCSs), which are not sitting loose out in the open. They live inside these vital enclosures.

The panel contains very valuable equipment: the control systems themselves, power supplies, filters, and all the connectivity infrastructure that keeps a plant running, as well as cooling or heating systems when needed.

This basic role has not really changed over time. The cabinet protects and supports operations. Yes, it has evolved to become more secure, more robust, and better adapted to different environments. But at its core, the control panel is still the container that ensures the control systems inside can function reliably.

How Control Panel Components Have Changed Over Time

There have been distinct phases in the evolution of control system components. It started with pneumatic systems, which operated with air pressure of 20 pounds per square inch (psi) to 25psi. Then came electronic analog systems, and later, digital electronics.

The industry moved from transistors and basic electronics into microprocessors, industrial computers, PLCs, and DCSs. Today, we even have smart sensors and systems performing limited control at the field level.

Meanwhile, control hardware has become much more powerful. A modern PLC or DCS can do things that used to require separate systems.

The boundaries between these systems are blurring. A PLC might now handle process control, while a DCS could manage discrete operations. Additionally, supervisory control and data acquisition (SCADA) systems have evolved from isolated, reactive control hubs to highly interconnected, proactive, and intelligent platforms that are pivotal to digital industrial automation.

The role of SCADA systems will continue to expand as industries demand higher efficiency, resiliency, and agility in increasingly complex environments. With ongoing advances in connectivity, artificial intelligence (AI) capabilities, and edge/cloud integration, these systems are set to become even more intelligent, autonomous, and secure. They are central to the realization of Industry 5.0—enabling smart factories, grid modernization, and sustainable infrastructure management.

The evolutions of industrial control are all getting mashed together because of how powerful and versatile the technology has become.

But with that power comes complexity. These advanced components generate more heat, need more precise power delivery, and are vulnerable to environmental conditions. That is where panel design becomes critical.

Key Standards Panel Builders Must Follow

As control panels grow more complex and interconnected, adherence to rigorous standards is essential to ensure safety, performance, and cybersecurity. There are several to consider: the National Electrical Code (NFPA 70), UL 2900, International Electrotechnical Commission (IEC) standards, and cybersecurity-focused standards like IEC 62443. Some focus on safety for operators and installers, while others ensure performance and security.

Some standards are construction-focused and govern the panel builder's job. Other standards are to be followed by manufacturers of control system components—including those around fail-safes and electrical reliability. Here’s a closer look at the leading standards:

• NFPA 70, better known as the National Electrical Code (NEC), is the most widely adopted electrical safety standard in the US. It governs the design, installation, and inspection of electrical systems, including industrial control panels.
• UL 2900 is a US cybersecurity standard specifically designed for industrial control systems and industrial control panels. It provides a testing framework to validate that devices resist cyber threats and comply with operational technology (OT) security best practices.
• IEC 62443-4-1 is a critical industrial cybersecurity standard that defines secure development requirements for components used in industrial control panels, PLCs, RTUs, and other automation systems. Unlike general information technology (IT) security standards, it focuses specifically on OT environments.

Some of these standards have been around for decades and are now baked into modern design tools like AutoCAD Electrical or EPLAN. Still, the builder must consider best practices, such as separation between high- and low-voltage wiring, shielding, and grounding, especially when modules require fail-safes or redundancy.

Cybersecurity standards are evolving the fastest. Panels are now network-connected and vulnerable. That means the standards are changing to keep up with those evolving risks.

Control Panel Building is an Art with Scientific Challenges

In the past, building a control panel was a real craft. It was based on the experience of the technician, who knew how to lay out and wire the system. Today, software tools streamline much of that process. But there is still an art to it.

What makes the difference now is how designers accommodate client needs, environmental constraints, and future expansion—all within limited space. Designers need to balance everything: accessibility for maintenance, clear labeling, airflow for thermal management, and cable routing that allows efficient wiring.

Designing a panel is like being a software engineer. Designers are handed building blocks and told to create something specific and optimized. The challenge is knowing how best to put it all together.

Key Considerations for Thermal Management

As systems get more powerful, they generate more heat. Designers need to manage that or risk destroying critical electronics. The first line of defense is passive cooling; that is, allowing for airflow. But when that’s not enough, designers need fans or even air conditioners inside or outside the panel.

There are also hybrid systems that rely on passive cooling until a specific temperature is reached, then kick in active systems. In extreme environments, such as liquefied natural gas (LNG) plants on floating ships or applications in outdoor deserts or freezing temperatures, designers might even need heating systems to prevent condensation and frost damage.

Condensation, in particular, is a killer. Warm, humid air enters a panel during the day and cools at night. Without proper heating or ventilation, it condenses inside the panel, damaging components. Designers have to understand the environment the panel will live in to choose the right cooling or heating solutions.

Best Practices for Wiring and Connectivity

Wiring inside panels must be organized and separated by signal type—power, analog, digital—to prevent interference and confusion. Density has increased with modern modules. However, the wires must still be large enough to be safely handled, even with gloves on.

Labeling is crucial. Every wire and terminal should be marked clearly and consistently. Documentation must match the physical layout so wiring and maintenance can be done quickly and safely.

The industry is also seeing more use of multi-pin connectors and fieldbuses—digital systems that let multiple devices share the same communication line—which help reduce wiring complexity. These allow large bundles of signals to be routed through a single connector. Wireless is gaining ground, too, mostly for monitoring rather than control, due to concerns over reliability and hacking. This shift further reduces wiring density inside the panel.

Panel designers need to be creative in fitting all these connections, power supplies, cooling systems, and even antennas into increasingly compact enclosures without sacrificing performance or safety.

Final Thoughts

Panels may be simple in theory—they are boxes that hold electronics—but in practice, they represent a real engineering challenge. With more contained intelligence, power, data, and complexity than ever, building a reliable, scalable, and safe panel means mastering both the fundamentals and the latest trends. From wiring to cooling and labeling to layout, there is still a deep art to doing it right.

In the next article, we’ll dive into where control panels are headed—AI, digital twins, sustainability, and the fast-moving shift from Industry 4.0 to 5.0 and beyond.