Plan power and cabling early
Power and cabling are the least visible parts of an exhibit and among the hardest to change afterward. Cutting into a finished gallery wall or lifting a display case floor is expensive, and in heritage buildings it may not be allowed. The best moment to decide where cables go is before walls, plinths and cases are built.
This article offers general planning ideas. Electrical work in public buildings is regulated, and it should be designed and carried out by qualified people following local rules. Treat anything here as background for conversations with them, not as instructions for doing electrical work yourself.
Start with a list of what needs power
Make a simple table for each exhibit: screens, computers, speakers, amplifiers, lighting, sensors, network switches and any motors or other devices. Note the power each uses, where it sits, and whether it needs to be on all day or only during opening hours. Manufacturers list power draw on data sheets or labels, and the numbers often differ between idle and full load.
Add up the total for each circuit and leave generous headroom. Equipment tends to be added over time, and a circuit that is nearly full on opening day becomes a problem later. Ask the electrical professional to confirm how many circuits are needed and how they should be divided.
Consider the following:
- Dedicated circuits. Putting exhibit equipment on its own circuits, separate from cleaning sockets and temporary equipment, can reduce accidental disruption.
- Clean shutdown. A sudden power loss can corrupt computers. Small uninterruptible power supplies can allow a computer to shut down gracefully, though they need battery checks and replacement.
- Scheduled power. Timers or building control systems can turn equipment on and off each day. Some devices need a proper shutdown rather than being cut off, so check the manufacturer’s advice.
- Power switches. A clearly labeled master switch for each exhibit helps staff, and it should be reachable without dismantling anything.
Understand signal cables
Power is only half the story. Video, audio, network and control signals each have their own cables and limits.
Video. Common video connections work well over short distances, but signal quality can degrade on long runs. Beyond a certain length, cables may need extenders, active cables or a different method such as sending video over a network cable. The limits depend on the resolution and the cable type, so check the specifications for the exact setup. This links to the screen choice in display types.
Audio. Sound signals are sensitive to interference. Keep audio cables away from power cables where possible, and cross them at right angles when they must meet. Balanced audio connections resist interference better over long distances.
Network. Ethernet has a distance limit, commonly given as around 100 meters per run. Details of planning are covered in exhibit networks.
Control and sensors. Buttons, sensors and lighting controls often use low-voltage wiring. Label them clearly, because they are easy to confuse with data cables.
Avoid unnecessary adapters and joints. Each connector is a potential point of failure, and loose ones are a common cause of mysterious faults.
Separate power from signal
Running power and signal cables side by side for long distances can cause interference, particularly for audio and analog video. Keep a sensible gap between them, use separate channels in a cable tray or conduit where possible, and follow the advice of the installer. Where crossing is unavoidable, cross at a right angle.
Route the cables where you can reach them
Hidden wiring is tidy, but hidden wiring that cannot be reached is a liability. Think about:
- Conduit. Empty pipes through walls and floors let you pull new cables later without breaking anything open. Adding a spare conduit during construction is cheap compared with retrofitting.
- Access panels. Place removable panels at junctions and at each exhibit, big enough for a hand and a tool.
- Plinths and cases. Leave space at the base for cable slack, a power strip fixed in place and a route out. Avoid designs that need the display case to be lifted to reach plugs.
- Floor boxes and trunking. Recessed floor outlets or low-profile trunking keep cables off the floor in open galleries, but make sure they are rated for public traffic and cleaning.
- Slack. Leave a loop of extra cable so that equipment can be pulled out for service without disconnecting.
Trip hazards matter especially in public spaces and for visitors who use mobility aids or have low vision. Avoid loose cables across walkways, and use proper cable covers only as a temporary measure.
Safety and heat
Keep power strips and power adapters off the floor where they might get wet or cleaned over. Do not cover them, and do not chain extension leads together. Equipment in closed plinths generates heat, so allow ventilation and avoid packing cables tightly around hot parts. Cables in public areas should be of appropriate fire-safety type for the building, which the installer or building manager can confirm.
Think about children too. Exposed sockets, adapters and cables within reach should be avoided. Mounting and enclosure design, covered in screen enclosures, helps keep everything out of hands.
Label and document everything
Label both ends of each cable and each circuit. Take photos before closing walls or plinths. Keep a simple map showing circuits, switches, cable runs and the location of access points. Include equipment lists with power draws and model numbers. This is the sort of material that belongs in project handover, and it saves hours when a fault appears years later and the original installer is no longer available. A good record also makes it easier to move equipment for touring exhibits or a gallery refit.