10 Most Frequently Asked Customer Questions about DALI Systems?

1. Why don’t the lights turn on or off?

Common causes: No mains power to luminaires, no DALI bus power, short/open circuit on the bus, or all devices in “system failure” mode.
Troubleshooting: Check mains voltage at fixtures. Measure DALI bus voltage (should be 16–22.5V DC). Power cycle the entire system. Test broadcast commands first.

2. Why do only some lights respond while others don’t?

Common causes: Wiring break/open circuit affecting part of the line, faulty driver in one fixture, or excessive voltage drop to distant devices.
Troubleshooting: Measure bus voltage at non-responsive fixtures (<14V indicates issue). Check for loose connections or damaged cable sections.

3. Why are the lights flickering?
Common causes: Electromagnetic interference (EMI) from nearby power cables, noise on the bus, poor signal integrity, or incompatible/inferior drivers.
Troubleshooting: Separate DALI cables from mains power lines. Use shielded cable if needed. Test with shorter cable runs.

4. Why won’t the lights dim properly or smoothly?
Common causes: Incompatible drivers (e.g., minimum dim level too high), incorrect fade rates, or log vs. linear dimming curve mismatch.
Troubleshooting: Query driver parameters via commissioning software. Replace with certified DALI-2 drivers if needed.

5. Why is the DALI bus voltage too low (below 14–16V)?
Common causes: Excessive cable length/branches causing voltage drop (>2V max allowed), too many devices drawing current, or insufficient bus power supply.
Troubleshooting: Measure voltage drop end-to-end. Shorten runs, use thicker cable, or add a bus power supply (ensuring only one active per line).

6. Why is there a short circuit or open circuit on the DALI line?
Common causes: Miswiring (e.g., DALI wires touching mains), damaged insulation, or incorrect termination.
Troubleshooting: Disconnect sections sequentially to isolate the fault. Use a multimeter to check continuity and shorts.

7. Why are there duplicate or conflicting addresses after adding new devices?
Common causes: Random addressing clash or failed re-commissioning.
Troubleshooting: Use commissioning software to re-address or randomize unassigned devices.

8. Why can’t the system discover or address new devices during commissioning?
Common causes: Devices not powered, bus not energized, or conflicts with existing addresses.
Troubleshooting: Send “Initialize” and “Randomize” commands. Ensure bus voltage is present at new devices.

9. Why does the system stop working when more than 64 devices are connected?
Common causes: DALI limit of 64 addresses per line exceeded.
Troubleshooting: Split into multiple lines/subnets with separate controllers or routers.

10. Why does the bus current exceed 250mA or the power supply overload?
Common causes: Too many devices (each draws ~2mA), leaky/faulty drivers, or multiple bus power supplies fighting each other.
Troubleshooting: Measure total current. Remove devices or use separate powered lines. Ensure only one bus PSU per line.