Connected systems, data and flexibility are reshaping industrial electrical engineering
Automation and control are no longer functions added at the end of an electrical project. In modern industrial plants, they influence panel architecture, power distribution, circuit separation, component selection and the way the system communicates with machines, sensors and supervisory platforms from the earliest design stages.
The growing number of connected devices, the availability of real-time data and the need to modify processes quickly are making electrical systems more complex. A control panel must still manage power and protection, but it may also need to accommodate PLCs, communication modules, measuring devices, network components and operator interfaces.
This evolution is already visible in the systems described by Sices in its analysis of industrial automation and control systems, where PLCs, HMIs, SCADA platforms and industrial networks are treated as coordinated parts of the same infrastructure.
Why automation and control are changing electrical design
In traditional installations, many decisions could be made by focusing primarily on power ratings, currents, protection devices and distribution. These elements remain essential, but they must now be coordinated with broader functional and digital requirements.
The design team must understand which information will be collected, where it will be processed, which devices need to communicate and how the system should respond under different operating conditions. It must also define which functions must remain available if a data network is lost, a sensor fails or the supervisory system becomes unavailable.
The main requirements now include:
- integration of power, control and communication circuits;
- management of a growing number of sensors and intelligent devices;
- data exchange between PLCs, HMIs, SCADA platforms and management systems;
- local and remote access to operating information;
- protection of industrial automation networks;
- traceability of alarms, events and configuration changes;
- the ability to expand or reconfigure the plant;
- operational continuity and safe behaviour during abnormal conditions.
Automation and control therefore become cross-functional requirements connecting electrical engineering, software, cybersecurity, maintenance and production management.
Initial analysis must include system functions
Project quality depends on the completeness of the information collected during the first phases. In addition to electrical data, the design process must define operating sequences, machine or plant states, alarm conditions and the actions expected from operators.
A complete functional analysis should clarify:
- which equipment must be controlled;
- which variables must be measured;
- which sequences must operate automatically;
- which commands must remain available locally;
- how the system should behave after a power interruption;
- which permissions and interlocks must be verified;
- which data must be recorded and retained;
- which external systems must send or receive information.
The Sices electrical panel design process therefore needs to connect electrical specifications with functional requirements. A change in the process may affect the number of inputs and outputs, safety logic, network structure or auxiliary power demand.
Correct separation of power, control and communication circuits
Integration does not mean placing every component in the same space without a defined structure. In panels designed for automation and control, the separation of power circuits, analogue signals, digital inputs and network connections is essential for reliability and communication quality.
The internal layout must consider electromagnetic interference, thermal dissipation, component accessibility, cable bending radii and the ability to perform maintenance without affecting unrelated sections.
Drives, inverters, switching power supplies and contactors can generate disturbances that affect sensors and data lines. Component positioning, earthing, shielding and cable routing must therefore be designed as parts of the same electrical architecture.
Clear functional separation also supports diagnostics. When power supplies, signals and communications are correctly identified and documented, technicians can locate the source of a fault more efficiently and reduce intervention time.
PLCs, HMIs and SCADA platforms require a coherent architecture
The PLC manages operating logic and sequences, the HMI enables interaction with operators and the SCADA platform collects plant-level data, statuses and alarms. Their presence requires coordinated decisions from the beginning of the project.
The IEC 61131-3:2025 standard defines the syntax and semantics of the principal languages used for programmable controllers, including Structured Text, Ladder Diagram and Function Block Diagram. Standardised programming languages do not remove the need to define software structure, modularity, error handling and hardware interfaces clearly.
For this reason, automation and control should be developed together with the electrical schematics. Addresses, I/O lists, signal descriptions and communication methods must remain consistent across documentation, wiring and software.
A change made at only one of these levels can create discrepancies that are difficult to identify during testing or after commissioning.
Industrial networks and device interoperability
Industrial Ethernet, fieldbuses and open protocols make it possible to connect controllers, instruments, drives, protection devices and supervisory systems. This exchange of information expands plant functionality but also introduces new dependencies.
Electrical design must define network topology, speed, availability, redundancy and segmentation. It must also consider process behaviour when communication is lost: a device may retain its last command, stop, switch to local mode or enter a predefined safe condition.
Protocol selection cannot be based only on nominal compatibility. Designers must verify which data is actually available, how frequently it can be updated and how diagnostics, synchronisation and signal quality are managed.
In complex systems, automation and control therefore require a communication matrix identifying devices, exchanged variables, data direction, priorities and behaviour in the event of an error.
Operating data, measurements and information quality
Data is useful only when it comes from reliable measurements and is interpreted in the correct context. Current, voltage, temperature, pressure, flow, status and operating-time information can support supervision, maintenance and performance analysis.
Electrical design must provide suitable instruments, stable power supplies, signal protection and correct measurement scaling. It must also establish which data should be displayed in real time, which information should be stored historically and which conditions should generate alarms.
The integration described in the Sices article on intelligent electrical panels, remote monitoring and predictive maintenance shows that the value of monitoring depends on the ability to turn raw data into usable information.
An excessive number of unclassified alarms can make priorities harder to understand. A structure based on severity, cause, consequence and required action provides operators with clearer guidance.
Industrial cybersecurity as a design requirement
Connections between production systems, corporate networks and remote services increase exposure to configuration errors and unauthorised access. Cybersecurity must therefore be addressed during design rather than added only after start-up.
The IEC 62443 series was developed to secure industrial automation and control systems throughout their lifecycle. IEC 62443-3-2:2020 addresses security risk assessment for system design, including the division of an industrial system into zones and conduits.
From a design perspective, this means considering:
- segmentation between control and corporate networks;
- access management and different authorisation levels;
- protection of unnecessary ports and services;
- logging of relevant events;
- backup and recovery procedures;
- secure methods for remote support;
- configuration and update management.
Automation and control consequently require closer collaboration between electrical designers, software engineers, OT managers and IT teams, with responsibilities defined during the specification phase.
Functional safety and behaviour in the event of a fault
Process automation must be distinguished from safety functions while remaining operationally coordinated with them. Emergency stops, guards, enabling conditions and risk-reduction functions must be designed according to the hazard assessment rather than entrusted automatically to standard process logic.
IEC 60204-1:2016+A1:2021 applies to electrical, electronic and programmable electronic equipment and systems associated with machines and provides a reference for power supplies, protection, controls and documentation.
For machinery and related products placed on the European Union market, Regulation (EU) 2023/1230 on machinery will replace Directive 2006/42/EC when its main provisions become applicable.
The electrical project must establish what happens if power is lost, the PLC fails, communication is interrupted or a signal becomes inconsistent. Safe conditions should be defined and verified in advance rather than being interpreted only during software development.
Modularity and scalability for changing industrial plants
Production processes, recipes, capacity and machinery can evolve over time. A rigid system makes future changes invasive, while a modular architecture allows new functions to be integrated with a more controlled impact.
The scalability of automation and control concerns both hardware and software. Electrical panels may include reasonable spare space, reserve power capacity, communication ports and additional I/O capability. Software functions and devices can be organised into documented, reusable modules.
The evolution of automation and control also requires future expansion to be evaluated against the physical and electrical limits of the installation.
Modularity does not mean oversizing without criteria. It means identifying realistic developments and providing proportionate margins while maintaining control over heat dissipation, selectivity, short-circuit levels and auxiliary power capacity.
Digital engineering and consistent documentation
Increasing system complexity makes it more important to keep electrical schematics, layouts, bills of materials, I/O lists, network configurations and software aligned.
Digital engineering tools can connect information that was previously managed separately. In its article on digital twins and electrical panels, Sices describes the use of EPLAN to maintain consistency across schematics, layouts, wiring and documentation.
For automation and control systems, project documentation should include at least:
- updated electrical schematics;
- network architecture and addressing;
- input and output lists;
- descriptions of operating sequences;
- alarm, permission and interlock matrices;
- software and configuration versions;
- backup and recovery procedures;
- test reports and documented modifications.
Complete documentation reduces dependence on informal knowledge held by individual technicians and makes the entire system lifecycle easier to manage.
Testing operating scenarios, not only components
Testing an automated panel must verify wiring, protection and individual devices, but also the system response to expected and abnormal operating conditions.
Tests may include input simulation, output verification, sequence validation, alarm checks, communication-loss scenarios, restart after a power interruption and verification of different access levels.
Where practical, a Factory Acceptance Test can validate part of the system before installation. The Site Acceptance Test then verifies integration with the equipment, sensors and networks present at the actual site.
As explained in the Sices article on testing and commissioning of electrical panels, verification is not an isolated final step but a method for validating design decisions before full operation.
Commissioning and change management
During commissioning, automation and control are verified within the actual plant environment. This phase often reveals differences between specifications, site conditions and the real behaviour of connected equipment.
Every modification should be recorded and transferred to the final documentation. Changing a parameter, address or sequence without updating drawings and project files creates discrepancies that can become critical during future maintenance.
Software version management must also be structured. Backups, change logs and clear identification of the installed version make it possible to restore the system and understand the origin of changes in operating behaviour.
Electrical design for the complete system lifecycle
New requirements do not concern only plant start-up. A system must remain understandable, maintainable, monitorable and upgradeable for many years.
Lifecycle-oriented design considers component accessibility, spare-part availability, version compatibility, upgrade paths and the clarity of diagnostic information.
Automation and control therefore change the role of the electrical panel: from a distribution and command point into an infrastructure where power, logic, data and communications must remain consistent.
The quality of the final result depends on designing these dimensions as parts of one system and defining requirements, responsibilities, operating scenarios and validation criteria from the beginning.
