Track Systems · Standards
DALI + Emergency Lighting Track: How 8-Wire Track Works
How 8-wire DALI + emergency lighting track works: three phases, a DALI pair and a separate emergency phase in one profile, when to use it and what to specify.
What Is a Three-Phase Lighting Track and How Does It Work?
A plain-language reference to the most common lighting track in Europe: what it is, what is inside it, how an adapter picks its phase, and which standard it follows.
A three-phase lighting track is an aluminium profile with four insulated conductors — three live phases, L1, L2 and L3, and a shared neutral — into which luminaires are clipped with an adapter. Each luminaire takes power from one of the three phases, so three groups of lights can be switched or dimmed separately on the same track. The protective earth runs through the aluminium body. The track is rated 230 V per phase, 400 V between phases, and up to 16 A per phase under IEC/EN 60570. It is the most widely used lighting track in European shops, galleries and offices.
Key facts
| Also called | 3-phase track, 3-phase track, 4-wire track, three-phase busbar |
|---|---|
| Conductors | L1, L2, L3, N (four), earth on the profile |
| Rated voltage | 230 V to neutral, 400 V between phases |
| Rated current | Up to 16 A per phase |
| Standard | IEC 60570 / EN 60570 |
| Body | Extruded aluminium, powder-coated |
| Usual lengths | 1, 2, 3 and 4 m, joined with couplers |
| Mounting | Surface, recessed, trimless, suspended, wall |
| Typical colours | Black, White, Custom colour |
| Typical uses | Retail, galleries, museums, hospitality, offices, showrooms |
How does a three-phase track work?
The track works like a long power outlet that runs the length of the ceiling. Power enters at a feed, travels along the copper conductors inside the profile, and leaves through adapters wherever luminaires are clipped in.
- Feed. An end feed or middle feed connects the building cable to the four conductors and the profile earth.
- Distribution. The conductors run in insulating carriers on the inner walls of the profile, out of reach of fingers.
- Adapter. The luminaire hangs on an adapter that is pushed into the open slot of the track and locked with a lever.
- Phase selection. A selector on the adapter decides which live conductor, L1, L2 or L3, the luminaire uses. The neutral and earth contacts are always connected.
- Control. Each phase is wired to its own switch, dimmer or breaker, so the luminaires on L1, L2 and L3 form three independent groups.
What is inside the profile?
| Conductor | Function |
|---|---|
| L1 | Live, phase 1 |
| L2 | Live, phase 2 |
| L3 | Live, phase 3 |
| N | Neutral, shared by all three phases |
| PE | Protective earth, via the aluminium profile |
The profile is asymmetric. A groove or rib on one side, often called the earth or polarity side, means an adapter fits only one way round, so the neutral and earth contacts always meet the right conductors.
What are the three phases used for?
The three phases let one track carry three lighting groups that are switched separately. Common uses:
- Day, evening and night in a shop: full accent light, reduced light, and a window phase that stays on after closing.
- Zones along one long track: front, middle and back of a gallery.
- Function: spotlights on L1, wall washers on L2, a sign or pendant on L3.
- Load sharing: spreading many luminaires over three phases of a 400 V supply.
What voltage and current does it carry?
| Rating | Value | Note |
|---|---|---|
| Voltage, phase to neutral | 230 V AC | What every luminaire sees. |
| Voltage, between phases | 400 V AC | Only when fed from three phases. |
| Current per phase | 16 A max. | IEC/EN 60570 limit per conductor. |
| Power per phase at 16 A | 3,680 W | Plan for about 80%, 2,900 W. |
| Total, all phases on one phase | 16 A | The shared neutral carries the sum. |
Details on loads, breakers and the shared neutral are in our guide to track installation, spans and load limits.
How does a track adapter choose its phase?
An adapter is the plug between track and luminaire. A standard three-phase adapter has a phase selector, a locking lever and three contacts: one live, one neutral and one earth. When the lever is turned, the contacts rotate out of the adapter body and press against the chosen live conductor, the neutral and the profile. Adapters exist for different currents — for example the 6 A slot-connection adapter and the 10 A screw-connection adapter — and as driver adapters with an LED driver built in, such as the 32 W driver adapter GT-4W-DA32. A mechanical adapter has no contacts and only carries weight.
How does it differ from 1-phase and DALI track?
| Track | Conductors | Groups | Control | Typical use |
|---|---|---|---|---|
| 1-phase, 2-wire | L, N | 1 | On/off, phase-cut dimming | Homes, small shops, stands |
| 1-phase, 3-wire | L, N, PE | 1 | On/off, phase-cut dimming | Where a separate earth conductor is required |
| 3-phase, 4-wire | L1, L2, L3, N | 3 | Per phase | Retail, galleries, offices |
| 3-phase DALI, 6-wire | L1, L2, L3, N, D+, D- | 3 phases + up to 64 addresses | Per luminaire, DALI | Retail with scenes, museums |
| DALI + emergency, 8-wire | L1, L2, L3, N, D+, D-, E+, E- | As DALI + emergency phase | DALI, emergency | Public buildings, escape routes |
For a buyer's comparison of the two most common choices, see 3-phase vs DALI track.
Which standard covers three-phase track?
IEC 60570, adopted in Europe as EN 60570, is the product standard for electrical supply track systems for luminaires. It applies to tracks with two or more poles, a rated voltage up to 440 V and a rated current up to 16 A per conductor. It covers the track, the feeds, the connectors and the adapters, and tests protection against electric shock, earthing, terminals, mechanical strength, heat and fire resistance. The ENEC mark on track shows that an independent certification body has tested it to this standard. The installation itself follows IEC 60364 and its national versions.
How is it mounted?
- Surface: screwed or clipped to the ceiling — GT-4W-T.
- Recessed: set into the ceiling with a visible flange — GT-4W-TR.
- Trimless: plastered in flush, no visible edge — GT-4W-TT.
- Suspended: hung on wires or rods — wire suspension kit GT-4W-SU.
Glossary
- Adapter
- The plug that connects a luminaire to the track and selects its phase.
- Driver adapter
- An adapter with an LED driver built in, so the luminaire head needs no driver of its own.
- Feed
- The part where the building cable connects to the track, at the end or in the middle.
- Coupler
- Joins two track lengths in a straight line, conductors and earth included. An insulated coupler separates them electrically.
- Connector
- Joins track lengths at a corner (L), a branch (T) or a cross (X).
- DALI
- Digital Addressable Lighting Interface, IEC 62386: a two-wire control bus for addressing and dimming individual luminaires.
Frequently asked questions
What is a three-phase lighting track?
A three-phase lighting track is an aluminium profile with four insulated conductors — three live phases (L1, L2, L3) and a shared neutral — into which luminaires are clipped with an adapter. Each luminaire takes power from one of the three phases, so three groups of lights can be switched separately on one track.
Why is a three-phase track called 4-wire?
Because it has four current-carrying conductors: three live conductors and one neutral. The protective earth runs through the aluminium profile itself and is not counted as a wire.
Is a three-phase track the same as a three-phase track?
The terms are used for the same product. The three phases can be connected to three phases of a 400 V supply, but they can also all be fed from one phase. 'Three-phase' describes the track; 'three-phase' describes one way of feeding it.
What voltage and current does a three-phase track carry?
230 V between each phase and neutral, 400 V between phases when fed from three phases, and up to 16 A per phase, the limit set by IEC/EN 60570.
How does a track adapter choose its phase?
The adapter has a selector, usually a small switch or rotating contact, set to L1, L2 or L3. When the adapter is locked into the track, its contacts turn out and touch the chosen live conductor and the neutral, and an earth contact touches the profile.
Which standard applies to lighting track?
IEC 60570, adopted in Europe as EN 60570, covers electrical supply track systems for luminaires with two or more poles, up to 440 V and 16 A per conductor.
Can I mix brands of three-phase track and adapters?
Many European three-phase tracks share a common adapter format, but the profile shapes differ in detail. Mix brands only where the track maker lists the adapter as compatible, because a poor fit can break the earth contact.
