E Tech Group’s Guide to Best Practices for Designing a Control System Panel
Even the best automation systems don’t add up to much if the HMI is inadequate. Whether it’s difficult to access industrial data analytics, equipment aren’t communicating with sensors, or the control system panel is unable to present data saliently, a poorly-conceived control system panel can render otherwise well-designed building automation system a risk to operations and reputation.
Designing and fabricating custom control panels isn’t something every automation system integrator is experienced with, and this can contribute to subpar design. E Tech Group provides clients with this often-missing piece in automation implementation: control panels tailored to your facility’s needs.
What Should a Proficient Control System Panel Do?
There are several factors to consider when drafting a new control system panel, because there are several things a well-designed system panel should be able to do:
Monitoring & Data Acquisition
Control system panels gather data from sensors and other devices to provide real-time insights into the status of industrial processes. This data is often displayed on screens or gauges, allowing operators to monitor critical parameters such as temperature, pressure, flow, and speed.
Process Control & Regulation
Control panels incorporate PLCs, which are the “brains” of the control system. PLCs receive data from sensors and interpret it based on pre-programmed instructions. They then send commands to actuators, such as valves, motors, and pumps, to regulate the behavior of industrial equipment and maintain desired process conditions.
Human-Machine Interface (HMI)
Control system panels often feature HMIs, which provide operators with a user-friendly interface for interacting with the control system. HMIs allow operators to view process data, modify parameters, and troubleshoot issues, enabling them to effectively manage industrial processes.
Safety & Alarm Systems
Control panels often incorporate safety interlocks and alarm systems to prevent hazardous situations. These systems can detect abnormal conditions, such as excessive temperatures or pressure spikes, and trigger alarms or activate safety measures to protect equipment and personnel.
Communication & Networking
Control system panels can communicate with other devices and systems through various communication protocols, such as Ethernet, Modbus, and Profibus. This networking capability allows for centralized control and data exchange, enabling integration with supervisory control and data acquisition (SCADA) systems and other enterprise-level management software.
Regulatory Framework to Apply in Panel Design
Panel design must adhere to or exceed NEC, NFPA 70, and UL 508 and the newer UL 60947-4-1 industry standards for control system panel architecture. This requires an automation integrator with a breadth of expertise in system panel frameworks across industries.
NEC (NFPA 70)
The National Electrical Code (NEC), also known as NFPA 70, is the primary electrical safety standard in the United States. It covers the design, installation and maintenance of electrical systems in all types of buildings and structures. While the NEC is not a law in itself, it is widely adopted by state and local governments as mandatory code.
The NEC includes several provisions that specifically regulate facets of the design of control system panels in Article 409:
- Panel enclosure and protection
- Component selection, rating and installation
- Wiring and cabling
- Grounding and bonding
- Overcurrent protection
- Labelling and identification
- Access and maintenance
- Hazardous location considerations
- Compliance with manufacturer’s instructions
- Compliance with state codes and regulations
The NEC/NFPA 70 offers the broadest coverage of safety regulations applicable to industrial control system panels.
Also known as the “Electrical Standard for Industrial Machinery,” NFPA 79 provides comprehensive guidelines for the design, installation and maintenance of electrical equipment and systems used in industrial machinery. While NFPA 70 addresses general electrical safety requirements, NFPA 79 specifically focuses on the safety of electrical systems in industrial machinery applications.
Key regulations set forth by NFPA 79 for control system panel design draws on NFPA 70 as a foundation, and sets further requirements that apply specifically to architecture and installation of control system panels. NFPA mainly delves into the electrical work, offering guidelines on wiring gauge and installation, wire trays, conduits, and also requires all control system panels be designed to operate at 600V or less.
UL 508 & UL 60947-4-1
UL 508 was the industry standard for designing and installing a control system panel for decades, but has slowly been phased out and replaced by UL 60947 in the last few years. The UL 60947 standards are a revision meant to harmonize industry standards between the US, Canada and Europe in order to streamline global manufacturing and commerce.
However, if a control system panel was fabricated before the code switch (27 Jan, 2017) and complies only with UL 508, it is grandfathered in.
Some areas of control system equipment covered by these standards include:
- Product testing and qualification
- Industrial voltage regulation
- Control circuit design
- Guidelines for power circuit wiring
- Branch protection
- Group motor design
Environmental Aspects to Consider in Panel Design
A facility’s automation system doesn’t happen in a vacuum; there are physical parameters that need to be addressed, especially when it comes to workplace safety. Physical design aspects to factor into schematics for a new control system panel are:
Spatial Requirements for Enclosures
Where is the control system panel going to go? What kind of enclosure will be used? There needs to be enough room and outlets inside the panel enclosure so that it can be wired and worked on. Is it a cabinet enclosure? Factor in swing distance for the doors. Is it a high-temperature location? Ensure there’s proper cooling and ventilation measures taken.
Operator devices might be anything from an indicator light to an intricate touchscreen display. While a more intricate HMI might allow for more complex interactions, keeping things as simple as possible is important. An HMI must be user-friendly, without blind spots, and allow full access to the control system’s operations.
A control system panel must also include a physical emergency stop device that is not a button on the HMI, per OSHA regulations.
Supply Conductors & Overcurrent Protection
The supply conductor needs to be designed so that if every single apparatus in the system were running, it could still handle the load. This requires an understanding of the sum of all those connected apparatus’ is, so a buffer can be added.
Overcurrent protection is for what happens if the system panel receives more power than it’s rated for. This device protects the electrical components of the panel from overload. The control panel can be designed to include overcurrent protection, or it can instead be a discreet device, which may make it more convenient to access.
Front Panel Construction
There must also be physical parts that protect the control system panel itself from everyday operations. Face plates should resist water, high temperatures, chemicals, cleaners, and, if applicable, extreme weather. Because front panels/plates include user guidelines, they must also be designed to remain readable for the foreseeable lifespan of the panel.
Best Practices for Implementing a Control System Panel
Just like anything in industrial automation, when it comes to designing a control panel, the devil is in the details. A thorough approach to project strategy, schematics, fabrication, and installation is absolutely vital to implementing a cutting-edge control system panel. Key practices E Tech Group automation engineers apply to these projects include:
Placement and organization of the interior components of the control system panel are crucial to everything from daily operations to troubleshooting to reconfigures and upgrades. Organizing circuits and components like PLCs correctly is a balance of
- ensuring temperature grade inside the panel is coolest at the bottom so heat can escape through the top, and
- making sure the way everything is laid out is clear and intuitive to the user.
Component spacing is important. In theory, it might seem logical to minimize the size of the panel and enclosure to use the least space possible, but in practice that is not true. A larger panel is almost always better.
Panel size will depend on the number of components, wiring, location, and what layout is ideal for safe, accessible usage of the panel. There should be a generous amount of space for the current setup; this makes troubleshooting, reconfiguring, expanding or upgrading the current control system much simpler.
Wiring should be organized and wireways should be set up so that, should every I/O terminal be in use in the future, the layout would still work. This streamlines the process of adding new pieces of equipment.
There is no such thing as too much labelling when it comes to building a control system panel. Each item should be clearly and concisely labelled with a syntactical system that corresponds with each part’s PLC. Labelling is important for daily use, but especially for troubleshooting.
E Tech Group: Intuitive Control System Panel Fabrication & Implementation
As a North American leader in automation engineering services, one of our unique capabilities is designing and fabricating custom control panels tailored to the goals and obstacles of a specific facility.
Even within the same industry, different buildings have different parameters that affect what makes the best automation system and, in turn, the best control system panel. E Tech Group’s team works closely with yours to model and build the ideal system panel for your enterprise.
As a CSIA-certified integrator, our automation services adhere to the highest industry standards, and our deep domain expertise in regulatory compliance means you can rest assured your operations exceed compliance benchmarks. Ensure you get the most of your newly-integrated control system with a panel designed to help your company reach its goals.