Two Control Panels for an Industrial Pre-Heater System

Sometimes a project photo says what a paragraph can’t. Those rows of solid state relays aren’t decoration. Each one controls a heater circuit in a two-panel system we built for an industrial pre-heater application, and there are 24 of them total across two voltage levels.

Our scope covered the full controls package: electrical design, panel fabrication, PLC programming, and HMI development. The customer needed a modernized replacement for aging controls, and we delivered a clean, well-documented system built to run reliably for years.

The electrical design used a circuit breaker layout throughout with no fuses, spring terminal wiring, and filtered panel fans for air circulation. We also developed a complete documentation package: electrical drawings, a panel ringout checklist, a startup validation checklist, and a controls user’s guide.

These panels were replacing a system that had been running for roughly 20 years, and the new hardware had to drop in using the same connectors as the original. That meant reverse-engineering the existing wiring interface, ensuring every connection was keyed correctly, and matching the pinout of a system old enough to predate most of the components we were installing. The PLC and HMI software were written from scratch to run on the new platform.

The density of the heater control section is worth a mention. Twenty-four solid state relays across two voltage levels requires careful layout to keep things serviceable. Everything in these panels was laid out so a technician can find what they’re looking for quickly, replace a component without disturbing the rest of the wiring, and understand what they’re looking at without calling someone from engineering.

Rittal enclosures and the Satie back plate system gave us a solid platform to work from. Good hardware at the start makes the whole build easier and the end result more consistent. That same logic applies to the code: well-structured programs, written in Studio 5000 with clear documentation, are a lot easier to hand off and support.

This project is a good example of what the controls side of CGT does at its best. Not just building panels, but designing, programming, documenting, and delivering a system someone can actually own and operate long after we’re gone.