Operating several dimmable ECGs in one luminaire may cause an appearance of interference, due to inappropriate conditions.They may in turn lead to flickering, jerky dimming or, at worst, to a shut-down of the ECGs. The reason is coupling between the lamp circuits of multiple ECGs. If a lamp, running at 100 %, transfers only 1 % of its current into the neighboring lamp dimmed to 1 %, this represents a fault of 100 %.
The same applies to coupling between a heating circuit, i.e. feed and return lines to one side of a lamp, and the neighboring lamp circuit. There should be a minimum spacing of 12 cm between the lamp circuits (lamp and cables) of different ECGs. If this is not possible, the wiring must be installed carefully to reduce coupling between the lamp circuits to a minimum:
- Twist the cables of heating circuits with one another or make sure that they lie together closely. For 1-lamp ECGs (such as
QTi ... DIM) this is cables 21-22 and 26-27; for 2-lamp ECGs it is 21-22 and 21-23, 24-25 and 26-27. This is particularly important if neighboring ECGs are being operated at the lowest dimming setting
- Lay lamp cables close to the appropriate lamps so that the area 112 covered by the lamp circuit is as small as possible. The lamp circuits of two ECGs must not overlap. This is especially important for colour control applications if neighbouring ECGs are dimmed to different levels
- There should be several centimetres spacing between the lamp cables of two ECGs.
- The “short” lamp cables (see also ECG imprint, 1-lamp 26-27, 2-lamp 24-25 and 26-27) should lead to one side of the lamp and should be as short as possible; the “long” lamp cables should lead to the other side of the lamp (1-lamp 21-22, 2-lamp 21-22, 21-23)
- Mains and control cables should not be laid close to the lamp cables
- All the mains and control cables may be routed together. To ensure that RI suppression is not impaired there should be several centimetres away from the lamp cables
The better these recommendations are implemented, the more stable the light is at the lowest dimmer setting, even with a very small lamp spacing.
It will also be possible to make full use of the temperature range of the ECGs.
