Standards · Track Systems
How to Specify Lighting Track in a Tender
How to write a lighting track specification for a tender: system type, standard, rating, profile, finish, earth path, accessories and a clause you can copy.
DALI + Emergency Lighting Track: How 8-Wire Track Works
Escape-route lighting usually means a second set of luminaires on its own wiring. An 8-wire track carries the emergency supply in the same profile, so the escape lighting can hang on the same run as the display lighting.
An 8-wire DALI + emergency track carries three switched phases (L1, L2, L3), a neutral, a DALI control pair (D+, D-) and a separate emergency phase (E+, E-) in one aluminium profile. Normal luminaires take power from the three phases and dimming from the DALI pair; escape-route luminaires take their supply from the emergency phase, which stays independent of the normal switching. Specify it where emergency luminaires should hang on the same run as the display lighting, for example in shops, malls and showrooms with track along the escape routes.
What the eight conductors do
| Conductors | Purpose |
|---|---|
| L1, L2, L3 | Three switched lighting phases, 230 V each, 400 V between phases |
| N | Common neutral for the three phases |
| D+, D- | DALI control pair: addressing, dimming, scenes, sensors |
| E+, E- | Separate emergency phase, independent of the switched phases |
The protective earth runs through the aluminium profile and is carried across every joint by the couplers and connectors.
Why combine emergency and normal lighting on one track
- One line on the ceiling. Escape-route luminaires hang on the same track as the display lighting, in the same finish, instead of on separate fixings.
- Layouts can change. When the shop floor is rearranged, escape-route luminaires can be moved along the track to follow the new routes, within the emergency lighting design.
- Less separate wiring. The emergency supply runs inside the track along its length; only the feed point needs the dedicated emergency supply.
How it is connected
- The three phases are fed from the normal lighting distribution, one or three phases.
- The DALI pair is connected to the DALI bus power supply and controller, as on a 6-wire DALI track.
- The emergency phase is fed from the building's emergency lighting supply, for example a central battery system, according to the emergency lighting design.
- Each luminaire's adapter takes the supply it needs: a phase and DALI for normal luminaires, the emergency phase for escape-route luminaires.
What the track does and does not do
The track carries the emergency supply; it does not make an installation compliant on its own. The emergency lighting design, the choice of luminaires, the emergency supply, and the testing and maintenance regime follow the national rules, such as EN 1838 (emergency lighting applications) and EN 50172 (emergency escape lighting systems) in Europe. Agree the design with the fire safety engineer before the track is ordered, and mark the emergency luminaire positions on the drawings.
When to choose 8-wire over 6-wire DALI track
| If the project… | Choose |
|---|---|
| Has emergency lighting on separate fixtures or wiring | 6-wire DALI |
| Wants escape-route luminaires on the display track | 8-wire DALI + emergency |
| Expects the escape routes to move with the layout | 8-wire DALI + emergency |
| Needs only switching, no DALI | 3-phase track, emergency lighting separate |
What to specify
- System: 3-phase DALI + emergency lighting track, 8-wire (L1, L2, L3, N, D+, D-, E+, E-), to IEC/EN 60570.
- Profile: G-Tracks 8-wire profile 35.2 × 41.2 mm, or equivalent with section drawing.
- Feeds, connectors and end caps of the same 8-wire system.
- Emergency supply and luminaire positions per the emergency lighting design.
- Run lengths cut, capped and fitted at the factory; earth continuity tested per run.
For the choice between plain 3-phase and DALI, see 3-phase vs DALI track; for writing the full clause, see how to specify lighting track in a tender.
Frequently asked questions
What is an 8-wire lighting track?
An 8-wire track carries three switched phases (L1, L2, L3), a neutral, a two-wire DALI control pair (D+, D-) and a separate two-wire emergency phase (E+, E-) in one aluminium profile. The emergency phase stays independent of the three switched phases.
Why put emergency lighting on the track?
It lets emergency luminaires sit on the same run as the normal lighting, in the same style and at the same height, instead of on separate wiring and separate ceiling fixings. Escape-route luminaires can also be moved along the track when the layout changes.
Does 8-wire track make the installation compliant?
No. The track only carries the supply. Compliance depends on the emergency lighting design, the luminaires, the emergency supply and the testing regime, which follow the national rules, such as EN 1838 and EN 50172 in Europe.
Can standard DALI parts be used on 8-wire track?
No. The 8-wire profile is larger and has its own feeds, connectors and end caps. Specify parts of the same 8-wire system for the whole run.
