Three-circuit track is the default solution for galleries, retail and hospitality because it does something no other system does as cheaply: it puts three independently controllable lighting circuits into one piece of extrusion, and lets you decide at the moment of install — not at design stage — which fitting sits on which circuit.

This guide covers what actually matters when specifying it: which brands physically interoperate, how to size circuits without nuisance tripping, how to get dimming or addressable control onto a track that was never designed to carry data, and how to choose beam angles and colour rendering for artwork. It is written for specifiers and installers, so it assumes you know what an MCB is.

The basicsWhat three-circuit track actually is

A three-circuit track carries five conductors in a single 230 V extrusion: earth, neutral, and three separate live conductors, usually labelled L1, L2 and L3. Every luminaire connects through an adaptor with a selector that assigns that fitting to one of the three lives. One run of track therefore gives you three independent zones without three runs of track.

You will see it sold as three-circuit, 3-phase or multi-circuit track. These usually describe the same product, but the "3-phase" label is misleading in most UK installations.

When three-circuit is the right answer

• Galleries and museums — hang layouts change; the track lets you move and re-zone fittings without an electrician touching the ceiling.
• Retail — separate circuits for window, feature and general merchandising, switched on different schedules.
• Hospitality — day/evening/late scenes from one run.
• Any space where the lighting layout is not yet decided — the single strongest argument for track over fixed downlights.

When it is the wrong answer

• You need more than three scenes, or per-fitting control. Go to a DALI or Casambi configuration instead (see control options).
• The ceiling is a listed or decorative surface where surface-mounted extrusion is unacceptable and there is no void for recessed track.
• Very high, inaccessible ceilings where the re-aiming benefit never gets used.

The question everyone asksCompatibility: what fits what

There is no single universal three-circuit standard, but there is a dominant one. Most of the market builds to the profile originated by Nordic Aluminium under the Global name, and the German Eutrac profile is dimensionally interchangeable with it. In practice, an adaptor built for one will physically fit and lock into the other.

That covers a large share of what is sold in the UK. It does not cover everything.

How to identify what you already have

If you are adding fittings to an existing installation and nobody knows the brand:

1. Count the contacts. Look into the open end (isolated first). Four contacts plus earth (L1, L2, L3, N) means standard three-circuit. Six plus earth, with two of them a closely spaced pair, means DALI track — those two are D+ and D−, and a standard adaptor must not be used. Two lives plus neutral means single-circuit, and no three-circuit adaptor will work.
2. Measure the outside width. Global/Eutrac profile is nominally 35 mm across the face. A materially different width means a different system.
3. Look at the earth position. On Global/Eutrac the earth contact sits asymmetrically to one side — this is what forces the adaptor to go in one way round.
4. Photograph the end profile and the adaptor. Send it to us and we will identify it — see the bottom of this page.

Our principal systemPowergear track in detail

Powergear is the three-circuit system we specify by default and hold in depth. It is a European manufacturer (Powergear Europe, based in Breda, Netherlands) producing to the Global-compatible profile, with ENEC, CE and UL certification and ISO 9001 / ISO 14001 manufacturing. The reason we lead with it is not price — it is that the accessory range solves problems the other systems make you work around.

Published specification (PRO-04xx standard track)

Electrical rating — the part that matters

Powergear rate the PRO three-circuit track at 230 V / 16 A per circuit (220–250 V, 16 A max for the EU market). But the way you feed it changes what you can actually draw:

Mechanical loading

Powergear's mechanical load diagram — identical for the standard and DALI ranges — gives support centres of 1,000 mm carrying point loads of up to 60 N (roughly 6 kg) each, with the first fixing set within about 100–200 mm of the end of the run.

That 60 N is per suspension or fixing point, not per metre. Most gallery tracklights are well inside it, but framing projectors and fittings with integral drivers are heavier than they look — check the fixture weight and tighten the support centres rather than assuming the standard spacing will carry it. The track itself adds 840 g per metre.

Getting past 16 A on a long run

Powergear supply an insulated coupler (PRO-0433A) alongside the standard one. It joins two track sections mechanically and keeps the profile continuous, but breaks electrical continuity between them — so each section can be fed separately from its own protective device.

For a long gallery run on a single-phase supply, this is the clean answer: split the run into electrically independent sections with insulated couplers, feed each one, and you are no longer constrained by a single 16 A neutral across forty metres of track. The ceiling still reads as one continuous line.

The Powergear range, by part number

Adaptors and Ultimate adaptors

Powergear supply adaptors both as loose components and as OEM parts to luminaire manufacturers. There are two families, and the distinction matters when you are pricing a fitting.

Plain adaptors — no driver

Ultimate adaptors — multi-current LED driver concealed inside

Specify by the drive current and wattage your luminaire needs. The multi-current range means one adaptor covers a band rather than a single fixed output.

Four things Powergear does that the alternatives don't

1. The same accessories fit surface and recessed track. Couplers, feeds and end caps are common across both. If a scheme changes from surface to recessed part-way through design — which happens more often than anyone admits — you are not re-specifying the whole accessory schedule.
2. Twisted L and T connectors. Powergear's corner and junction pieces handle the orientation change within the connector itself, so you need fewer distinct handed parts on the schedule. Fewer line items, fewer things to get wrong on site.
3. Cut and install, with no wire adjustment. The track can be shortened on site and is ready to install immediately — the conductors do not need trimming or re-seating. Combined with the EZCLICK mounting features, this is the difference between a fast install and a fiddly one.
4. Ultimate adaptors with the driver concealed inside. Moving the multi-current LED driver into the adaptor lets the luminaire body shrink, which matters in galleries where the fitting should disappear. The range covers plain, Triac-dimmable, DALI and tunable-white versions — detailed below.

AnatomySystem components

A track system is not one product, and incomplete schedules are the most common cause of a job stalling on site. A complete run needs all of the following.

Getting it right on siteCircuit selection and track orientation

The adaptor selects its circuit mechanically. Depending on the manufacturer this is a rotary selector, a small switch, or a choice of insertion position — but in all cases the selection is made relative to the physical orientation of the track.

This creates the single most common commissioning fault on track installations:

Planning your three circuits

Decide the zoning logic before install, because it drives how many fittings you need on each circuit:

• Gallery — Circuit 1: artwork accent. Circuit 2: general/circulation. Circuit 3: feature wall or reserve for future hangs.
• Retail — Circuit 1: window and entry. Circuit 2: feature displays. Circuit 3: general merchandising.
• Hospitality — Circuit 1: task and service areas. Circuit 2: table accent. Circuit 3: ambient/late scene.

Leaving one circuit deliberately under-loaded is good practice in galleries. It gives the curator somewhere to put the fittings for the next exhibition without re-zoning the whole run.

The calculationLoad calculation and the inrush problem

Track conductors are typically rated 16 A — Powergear PRO track is rated 230 V / 16 A per circuit, and most Global-compatible systems are comparable. The figure that catches people out is not the conductor rating but the effect of the supply configuration, covered in the Powergear section above: on a single-phase feed the shared neutral limits the whole track to 16 A total, not 16 A on each of three circuits.

Steady-state calculation

Which tells you that with LED, you will effectively never reach the thermal limit of the track. Nobody puts 98 spots on one run. The steady-state calculation is not your constraint.

The real constraint: inrush current

This is the part that gets left out of most guidance, and it is the reason otherwise-correct installations trip on switch-on.

Every LED driver contains input capacitance that charges the instant power is applied. The resulting inrush is very short — typically tens to a few hundred microseconds — but the peak can be tens of amps per driver, and the peaks of every fitting on the circuit coincide because they all energise at the same moment. A standard Type B MCB will trip at roughly three to five times its rated current, so a 16 A Type B device can be tripped by a bank of LED drivers whose combined steady-state draw is under 300 W.

In practice, the number of electronic drivers you can safely put behind one Type B 16 A MCB is often in the region of 15 to 25, depending entirely on the driver. Mitigations, in order of preference:

1. Read the driver datasheet. Look for peak inrush current (I_peak) and its duration (usually quoted at 50% or 90% of peak). Manufacturers who publish this are telling you they have thought about it.
2. Specify Type C MCBs (5–10× trip curve) rather than Type B for LED lighting circuits. This is the standard, cheapest fix. Confirm the earth fault loop impedance still permits disconnection within the required time — a Type C needs a lower Zs than a Type B.
3. Split across the three circuits. You have three; use them. This is free capacity you have already paid for.
4. Use a relay module with staggered switching or an inrush limiter for large installations, so the circuits energise sequentially rather than simultaneously.

Control strategySwitching, dimming, DALI and Casambi

Standard three-circuit track carries power only. There is no data conductor. Everything below is a way of working around that.

DALI on three-circuit track

DALI needs a two-wire data pair, and standard three-circuit track has no conductors to spare. The solution is a different extrusion — DALI track carries the data pair as additional conductors alongside the power circuits.

Powergear's DALI track (PRO-0610 series) carries six conductors plus earth: L1, L2, L3, N, D+ and D−. The important consequence:

• You keep all three power circuits. The DALI pair is additional, not substituted. Powergear's connecting diagram states 230 V 16 A max on a single-phase feed, or 3 × 16 A on three-phase — plus DALI signal. You are not trading power zoning for control.
• You gain individually addressable control of every fitting on the run, plus scene recall.
• It requires DALI-specific track, adaptors and fittings throughout. Standard three-circuit components are not interchangeable — see the warning below.
• The DALI bus needs a power supply and an addressing/commissioning exercise. Budget for the commissioning time; it is not a plug-in job.

Powergear produce a parallel DALI range rather than a conversion kit: PRO-0610 and PRO-0620 DALI multi-circuit track in 1 m and 2 m, with dedicated PRO-D631L and PRO-D631R DALI feed-in connectors in left- and right-hand earth configurations. Specify the DALI feed-in with the DALI track — a standard PRO-0431 feed will not give you a DALI bus. We stock the Powergear DALI three-circuit range and DALI tracklights to suit it.

Casambi as the retrofit route

Where the track is already installed and rewiring is not viable, Bluetooth mesh control puts the intelligence in the fitting instead of the wiring. Each luminaire contains a Casambi-enabled driver, the fittings form a mesh between themselves, and control comes from a phone or a battery-powered wall switch. No data conductors, no commissioning wiring, no DALI power supply.

Powergear address this through their Ultimate adaptor range, which houses a multi-current LED driver inside the adaptor itself and is available in a Casambi version. That combination is unusually useful for a gallery retrofit: the existing standard three-circuit track stays exactly where it is, the adaptor brings both the driver and the Bluetooth control with it, with no new wiring and no commissioning exercise. See our Casambi Bluetooth tracklights.

The trade-offs: control depends on a working mesh and an app, handover to a non-technical client needs care, and you are committing to a proprietary ecosystem. For a gallery that wants per-artwork dimming in a building it cannot rewire, it is usually the right answer anyway.

OpticsBeam angles and aiming

Beam angle is quoted as the angle at which intensity falls to 50% of the centre-beam value. To find the lit diameter on a surface:

Beam diameter in metres at common throw distances:

The 30-degree aiming rule

Aim accent fittings at approximately 30° from vertical. This is the museum default, and the reasoning is geometric:

• Shallower than about 20° and the beam grazes the surface, exaggerating canvas texture and frame relief, and throwing long shadows from the frame onto the work.
• Steeper than about 40° and the specular reflection off glazing or varnish lands in the eye of a viewer standing at normal viewing distance. This is the veiling reflection that makes glazed works unreadable.
• Around 30° keeps the reflected beam below the sightline of a standing viewer while retaining enough modelling.

Practically, this sets your track position: for a wall-hung work centred at 1.5 m above floor level on a 3 m ceiling, the track wants to sit roughly 0.8–1.0 m out from the wall. Track positioned tight against the wall forces a grazing angle you cannot correct with optics.

Light qualityColour rendering and conservation

What to specify

Conservation limits

LED sources emit effectively no UV, which removes one damage mechanism — but visible light still causes cumulative, irreversible fading. Conservation practice controls both illuminance and total annual exposure:

Sensitive material is additionally limited by annual exposure, commonly expressed in lux-hours per year — which is why galleries rotate works on paper rather than displaying them permanently. If you are specifying for a collection, the conservator sets these figures, not the lighting supplier. Your job is to provide fittings that dim smoothly to low output without colour shift, and to give the conservator the measured lux at the work.

From experienceSix specification mistakes

1. Ordering track without ends. Live ends and dead end caps are separate line items. A run without them is not installable.
2. Assuming the adaptor is included. Some fittings ship with an adaptor, some do not, and it varies within a single manufacturer's range. Check every line.
3. Sizing on wattage alone. The inrush current of the drivers, not the total watts, decides how many fittings sit behind one MCB.
4. Track too close to the wall. Sets a grazing angle that no optic will fix. Plan the track position from the aiming angle, not from the ceiling grid.
5. Mixing CCT or bin tolerance across a run. Ordering the same product in two batches months apart can produce a visible mismatch. Order the full quantity at once, or confirm bin consistency.
6. Specifying DALI track without allowing for commissioning. Addressing and scene-setting is a day's work with the right software, not a plug-in job.

Before you orderSpecification checklist

• Track system and profile confirmed (Global/Eutrac or proprietary), and all fittings confirmed compatible with it
• Surface, suspended or recessed decided — and for recessed, ceiling void depth verified
• Total track length calculated, including allowance for cutting
• One live end per electrically separate run; one dead end per open end
• Coupler count and handedness reconciled against the number of joints
• Adaptors accounted for on every luminaire line
• Circuit zoning agreed with the client, with spare capacity on at least one circuit
• Supply configuration confirmed — single-phase (16 A total) or three-phase (3 × 16 A)
• Long runs split with insulated couplers where the single-phase 16 A limit would be exceeded
• Driver inrush checked and MCB type (B or C) selected accordingly
• Control strategy fixed: switched, mains dimmed, DALI or Casambi
• If DALI: DALI track, DALI feed-in and DALI adaptors specified throughout — no standard components in the schedule
• Beam angles selected against actual throw distances and object sizes
• CRI, R9 and CCT specified; bin tolerance confirmed for consistency
• Conservation illuminance limits confirmed with the conservator, if applicable
• Lead times checked against the install programme

Common questionsFrequently asked questions

Can I put a single-circuit fitting on three-circuit track?

No. The adaptor geometry and conductor count are different. You need a three-circuit adaptor, which for most fittings is available as a separate accessory — so the luminaire itself may well be usable, but the adaptor must be changed.

Will an SLV fitting work on LEDsC4 or Powergear track?

Physically, yes — all three build to the Global/Eutrac profile. For a compliance-sensitive installation, confirm with the track manufacturer that the combination is approved, as mixing brands can fall outside the declared system conformity.

Does DALI track mean giving up the three power circuits?

Not with Powergear. Their DALI track (PRO-0610 series) carries six conductors plus earth — L1, L2, L3, N, D+ and D− — so the DALI pair is additional rather than substituted, and all three power circuits remain available at 230 V / 16 A per circuit. Other manufacturers implement DALI track differently, so check the conductor arrangement on the datasheet before assuming.

Can I use standard adaptors on DALI track?

No. The external profile is the same 35.2 mm, so the two are easy to confuse on site, but the internal conductor arrangement differs and the contact positions do not correspond. Fitting a standard adaptor to DALI track can put mains onto the data pair. Use DALI adaptors throughout and label the installation.

What is Powergear track rated at?

230 V / 16 A per circuit (220–250 V for the EU market). Note the supply configuration: on a single-phase feed the maximum is 16 A in total across all three circuits, because they share one neutral. On a three-phase feed you get 3 × 16 A. For long single-phase runs, use insulated couplers (PRO-0433A) to split the track into separately fed sections.

Do Powergear accessories fit both surface and recessed track?

Yes. Couplers, feeds and end caps are common across the surface (PRO-04xx), recessed (PRO-R4xx) and recessed trimless (PRO-TR4xx) ranges, so a change from surface to recessed during design does not force a new accessory schedule.

Will third-party spotlights fit Powergear track?

Powergear build to the Global-compatible profile at 35.2 mm, and most major brands' three-circuit adaptors fit. Powergear's current wording is "highly compatible with most major brands" rather than all, so for compliance-sensitive work confirm the specific adaptor before ordering.

How many spotlights can I put on one circuit?

Rarely limited by wattage with LED. The practical limit is driver inrush current tripping the protective device — often around 20 fittings on a Type B 16 A MCB, or roughly double that on a Type C. Check the driver datasheet for peak inrush before committing.

Can I dim three-circuit track?

Yes, three ways: mains dimming per circuit with dimmable drivers; DALI track for per-fitting control; or Casambi-enabled fittings that need no control wiring at all. Standard three-circuit track carries no data conductor, so per-fitting dimming always requires one of the last two.

What beam angle do I need for a painting?

Match the beam diameter to the work. At a 3 m throw, 15° covers about 0.8 m, 24° about 1.3 m and 38° about 2.1 m. Aim at roughly 30° from vertical to avoid reflections off glazing. Zoom optics are worth the premium where the hang changes.

What CRI do I need for a gallery?

Ra 90 as a floor, Ra 95+ for fine art — and always request R9 separately, as it is excluded from the Ra average and governs how reds and skin tones read. Where TM-30 data is published, use R_f and R_g in preference.

Can three-circuit track be recessed?

Yes, using a recessed mounting profile. Confirm the ceiling void depth before ordering — retrofitting recessed track into a finished ceiling is a building work, not an electrical one, and is usually more expensive than the lighting.

Can I cut track to length on site?

Yes, but only from the dead end. Cutting the fed end destroys the factory conductor termination. Re-cap the cut end and check the conductors are clean and undamaged before energising.

Browse the range

• Powergear three-circuit track system — the full range, or by finish: white, black, grey
• Powergear DALI three-circuit track
• Recessed three-circuit track and accessories
• Gallery track lighting — and the wider gallery and museum range
• Morpheos gallery tracklights
• Casambi Bluetooth tracklights
• DALI three-circuit tracklights
• Framing projector tracklights

Related reading: How to choose track lighting · Art gallery lighting · Book a free site visit

Last reviewed: August 2026. Figures for beam diameter are calculated from the 50% intensity beam angle. Electrical ratings and compatibility must be confirmed against the specific manufacturer datasheet for the products being installed. Installation work must be carried out by a competent person in accordance with BS 7671.