Making Sense of Complex Applications
For most installations, a standard control panel does the job. But what happens when it doesn't? Three real-world challenges that show how bespoke electrical design turns a problem into a solution.
When a door needs to manage fire safety over a live baggage conveyor belt, protect priceless museum artefacts, or integrate seamlessly across a national network of loading bays, standard off-the-shelf just won't cut it. Tim Drysch and GfA are trained experts in the unusual, the complex, and the unexpected. Our approach is to understand the environment, understand the challenge, and find the simplest integrated solution that works.
CHALLENGE 1
The Baggage Conveyor Fire Door
At a major international airport, fire shutters are required above baggage conveyor belts to prevent fire spreading between terminals. A straightforward requirement until you factor in what the belt is actually doing.
If the door closes while a suitcase is passing underneath, it comes to rest on the luggage, failing to create a smoke-tight seal and compromising its fire rating entirely. The system also needs to remain functional during a mains power failure.
The GfA Solution
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Intelligent Obstacle Detection:
- GfA implemented a PLC-based "handshake" between the door and conveyor system. When a fire alarm triggers, the panel checks whether a bag is blocking the photo beam. If it is, the conveyor moves forward or in reverse until the obstruction clears, only then does the door receive the signal to close.
- GfA implemented a PLC-based "handshake" between the door and conveyor system. When a fire alarm triggers, the panel checks whether a bag is blocking the photo beam. If it is, the conveyor moves forward or in reverse until the obstruction clears, only then does the door receive the signal to close.
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Battery Intelligence:
- The design incorporates a battery backup monitoring system that continuously checks voltage levels, triggering action automatically when batteries degrade to a critical threshold, so the door can always close when it needs to.
- The design incorporates a battery backup monitoring system that continuously checks voltage levels, triggering action automatically when batteries degrade to a critical threshold, so the door can always close when it needs to.
CHALLENGE 2
High-Security Logic
Museums housing cultural treasures and cash-handling centres require far more than a standard lock. These sites rely on heavy-duty physical locking mechanisms or bollards that engage when the door is closed.
The risk isn't just someone getting in, it's the door destroying itself. If a user attempts to open a door while heavy mechanical locks are still engaged, the motor can cause catastrophic damage to the curtain, and the system must verify the door lock status before giving a "secure" signal.
The GfA Solution
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Physical Verification:
- A strict logic sequence using a PLC and limit switches monitors the physical position of the locks. The door will not be permitted to open unless it receives a confirmed signal that all locks are fully retracted.
- A strict logic sequence using a PLC and limit switches monitors the physical position of the locks. The door will not be permitted to open unless it receives a confirmed signal that all locks are fully retracted.
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Fault Detection & Lockout:
- If the door closes but the locks fail to engage, perhaps due to misalignment, the system recognises the fault condition and locks out operation. Volt-free signals relay lock status and error states directly to control rooms, keeping security teams fully informed in real time.
- If the door closes but the locks fail to engage, perhaps due to misalignment, the system recognises the fault condition and locks out operation. Volt-free signals relay lock status and error states directly to control rooms, keeping security teams fully informed in real time.
CHALLENGE 3
The Universal Retrofit for Retail Logistics
A major retailer needed to upgrade loading bays across a large national network, each site with varying equipment configurations and legacy installations.
A single control panel had to integrate dock levellers, traffic lights, inflatable shelters, and door controls, consistently, across dozens of depots with different setups. The customer also needed to minimise time installers spent on-site, keeping disruption and cost to a minimum.
The GfA Solution
- Integrated Interlock Logic:
- GfA designed a modular combined panel with two built-in interlocks: the door cannot operate unless the leveller is in the parked position (confirmed via proximity sensing), and the dock cannot operate unless the door is open, preventing collisions and protecting both equipment and personnel.
- GfA designed a modular combined panel with two built-in interlocks: the door cannot operate unless the leveller is in the parked position (confirmed via proximity sensing), and the dock cannot operate unless the door is open, preventing collisions and protecting both equipment and personnel.
- Fitter-Friendly by Design:
- Panels were pre-wired and pre-tested before dispatch. On-site, clear connection diagrams make terminal-by-terminal wiring straightforward, no complex schematics to decipher, significantly reduced site time, and far fewer wiring errors.
- Panels were pre-wired and pre-tested before dispatch. On-site, clear connection diagrams make terminal-by-terminal wiring straightforward, no complex schematics to decipher, significantly reduced site time, and far fewer wiring errors.
See These Projects in Full Detail
Read the complete editorial — including additional technical detail and commentary from Tim Drysch — on the DIJ website, Spring 2026 issue.