Galvanic Isolation in DMX Networks — Equipment Protection and Signal Stability | Sundrax 🛡️
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In professional DMX installations, dozens or even hundreds of luminaires, controllers, splitters, and amplifiers are connected in a shared network through which the signal is transmitted. But what happens if a high-voltage surge ⚡️, for example, due to a short circuit, connection error, or even during a thunderstorm, enters one of the sections? Without galvanic isolation, such failures can damage or destroy all equipment across the network.
We spoke with a Sundrax engineer Alex Chomsky about how galvanic isolation works in DMX networks, why it’s essential, and where it must be implemented without fail.
Galvanic isolation is the electrical separation of connected devices while preserving signal transmission. In DMX networks, it is typically achieved using optocouplers (optical isolators) or transformers embedded in splitters, amplifiers, or interface modules.
- DMX Splitters: Each output is galvanically isolated, preventing short circuits from spreading across the network.
- DMX-USB Interfaces: Galvanic isolation between the computer and the DMX network reduces the risk of PC damage.
- Ethernet–DMX Transceivers (ArtNet, sACN): These protect the digital network from electrical surges traveling through lighting cables.
Why It Matters ⚠️
Without galvanic isolation, the entire DMX signal relies on a single ground. A voltage surge ⚡️ (even between two power phases on a stage) can create a potential difference that may damage or destroy interface equipment. This is especially critical for long cable runs or when power is drawn from different distribution boards.
Example 📌
One of Sundrax’s clients used a splitter without galvanic isolation for facade lighting. When a power supply fault occurred in one section, not only the end devices but also the controller inside the building failed. After upgrading to the Splitter Selective with full galvanic isolation, the problem was resolved. ✅
- Use splitters with galvanic isolation on every output (e.g., Splitter Selective Pro, Splitter Duo DIN).
- Implement interface modules with optical isolation.
- Avoid ground loops between different sectors of the installation.
- Separate power and DMX networks in large-scale projects.
We always recommend incorporating galvanic isolation in splitters. It’s a cost-effective protection against losses that can cost tens of times more. This is especially crucial for outdoor or distributed installations. 🏞️
If you’re unsure where or how to integrate galvanic isolation in your DMX system, Sundrax engineers are ready to help you select equipment and design a connection scheme with protection for all critical components. 🛠️
