Why Classification Comes Before Fixture Selection
Outdoor lighting is bought by installation, not by fixture. Two projects can use the same 12 W luminaire and still need different housings, cable, protection and control, because one sits on an eight-metre pole above a carriageway and the other in a planting bed at ankle height. Classifying the installation first is what makes quotations comparable.
Four questions decide the classification, and they are answered in order: what the space has to do, where the fixture sits, how it is powered, and how it is controlled. Each answer narrows the next. A path light at grade in a public park cannot use the same product family, marking or cable as a road luminaire, even when the photometric target looks similar on paper.
Axis 1: What the Space Has to Do
Function decides the photometric target, and the target decides the fixture family long before wattage is discussed. A carriageway is judged on luminance and uniformity at driving speed, a footpath on whether faces are recognisable a few metres away, a facade on how evenly a surface is grazed. Write the function first, one line per area.
| Space | What the lighting must deliver | Fixture family | Typical mounting position |
|---|---|---|---|
| Motorised road or carriageway | Luminance, uniformity and glare control at driving speed | Road luminaire on pole, single or double arm | 6–12 m, at the kerb line |
| Residential street or shared surface | Pedestrian and driver visibility at low speed, minimal glare into windows | Post-top or street luminaire | 4–6 m |
| Car park, apron or yard | Horizontal and vertical uniformity for vehicles, enough vertical light for cameras | Area or parking luminaire, pole or wall mounted | 6–10 m |
| Footpath, cycleway, steps | Safe movement at walking pace, no upward spill | Bollard, step or path luminaire | 0.6–1 m, spaced so beams overlap |
| Facade, bridge or monument | Even grazing or washing of a vertical surface | Wall washer or linear graze | On the wall or at grade, aimed along the surface |
| Planting bed, lawn or tree | Accent with narrow beams, controlled trespass onto neighbours | In-ground uplight, spike or lawn luminaire | At grade |
| Water feature or pool surround | Underwater or surround illumination with separated extra-low voltage | Submersible and ground-recessed luminaire | At or below water level |
| Perimeter, gate or security route | Detection plus camera-friendly light, minimal spill beyond the boundary | Floodlight, pole or wall mounted | 4–8 m, aimed inward |
Road and conflict-area lighting is commonly assessed against EN 13201, where M classes describe motorised traffic, C classes conflict areas and P classes pedestrian and cycle routes. Our note on dimming profiles and road lighting classes covers how those classes interact with an energy budget. One decision is already implied above the table: a fixture that stands in the ground, sits on a wall or mounts on a pole is a different product from one that hangs in the air.
Axis 2: Where the Fixture Sits
Location class describes what the environment does to the fixture: rain on an exposed wall, sprinkler spray at ankle height, soil contact, standing water in a paved recess, or the edge of a pool. The wiring code of the market where it is installed defines it, so the same fixture can be right in one country and wrong in another.
In North America, wet and damp locations are defined in NEC Article 100, and NEC 410.10(A) requires a luminaire installed in a wet location to be listed and marked for it. The marking is the compliance evidence. “Suitable for Wet Locations” assumes a mounting height of at least 4 ft (1.2 m) above grade; units intended lower carry a sub-marking such as “Suitable for Mounting Within 4 Feet of Ground”, and in-grade units “Suitable for Ground-Mounted Recessed”. An IP number alone does not satisfy it.
In IEC-based markets the evidence is an IP code declared under IEC 60529 together with the product standard for the family: IEC 60598-2-3 for road and street luminaires, 60598-2-5 for floodlights, 60598-2-13 for ground recessed luminaires and 60598-2-18 for pools and similar applications. Ground recessed luminaires also declare a rated static load and a maximum surface temperature, because vehicles roll over them.
| Where the fixture sits | What the environment does | IEC route (what is declared) | North American route (what is marked) |
|---|---|---|---|
| Exposed wall, 1.2 m or more above grade | Rain, wind-driven water, UV | IP code to IEC 60529 plus the family standard | Listing mark plus “Suitable for Wet Locations” |
| Wall or post below 1.2 m, in a sprinkler zone | Splash, runoff, soil wicking at the mounting point | IP65 or higher, with mounting instructions | Wet marking plus “Suitable for Mounting Within 4 Feet of Ground” |
| Stake or bollard at grade in planted soil | Soil contact, irrigation, knocks | IP65–IP67 and a declared impact rating | As above; low-voltage systems listed to UL 1838 |
| Ground recessed in paving, driven over | Static load, shear, water standing in the recess, thermal shock to glass | IEC 60598-2-13, static load and surface temperature marked | Wet marking plus “Suitable for Ground-Mounted Recessed” |
| Recess at a pool, fountain or water feature | Permanent moisture, chlorine, occasional immersion | IP67–IP68 plus IEC 60598-2-18 | Wet location listing for pool use, separated extra-low voltage |
| Luminaire head on a pole over a road | Rain, dust, wind; no soil contact | IP66 typical, IEC 60598-2-3 | Wet marking; cable entry and pole per local rules |
Two notes. A certificate is only as good as the model it names: ask whether the report covers the exact model and driver, and ask in writing which market it is valid for. And the marking is an installation condition, not a marketing claim: a wet-marked fixture with no ground sub-marking is still the wrong fixture at 300 mm above a lawn.
Axis 3: How the Installation Is Powered
Power class sets the electrical design. A mains circuit needs protection and earthing, a low-voltage landscape run needs voltage-drop control, and a solar pole needs an energy budget. It also decides who may work on the installation, and how much of the project cost sits in cable, trenching and civil work rather than in fixtures.
- Mains (line voltage). Fed from a distribution board with overcurrent, earthing and residual-current protection to the local wiring rules, with cable buried or mechanically protected. This class needs a licensed electrician and an inspection.
- Separated extra-low voltage (12 V or 24 V landscape zones). One transformer per zone, with cable sized for voltage drop rather than current rating: at 12 V a 1 V loss is over 8 % of the supply. Our wire size and voltage drop guide gives the formula and the run-length table. In North America these systems are listed to UL 1838.
- Off-grid solar, one system per pole. No supply cable, but a panel area, a battery sized for the worst month and a controller with a load profile. Dimming and autonomy must be fixed before the quotation. Dusk-to-dawn operation and DC surge protection are the two parts projects most often leave out, and panel area changes the wind load the pole carries.
Mixing classes on one site is normal, and that is where waste appears. A plaza with mains-fed facade lighting, a 24 V path circuit and eight solar poles is reasonable, but each zone needs its own drawing, protection and commissioning record.
Axis 4: How It Is Controlled
Control closes the loop, because it decides how much energy the installation actually consumes. A photocell, a time profile, a motion sensor, a colour controller and a telemetry gateway are five different control classes, with different implications for the driver, the cable and the energy budget, and the control class must be fixed before autonomy is calculated.
- Photocell (dusk to dawn). The simplest class: switch on at a lux threshold and run until morning, so the energy budget covers the whole night.
- Time profile or lighting-class dimming. Reduces energy in the late hours if written as numbers, for example 100 % until 23:00 and 50 % afterwards. See road lighting classes and curfew dimming.
- Motion (PIR or radar). Restores full output on detection. Fix standby level, hold time and sensitivity — see motion sensor dimming.
- Colour and effects (landscape). Single colour, RGB, RGB+W, DMX512 or wireless RF. Choose the protocol before the fixture, because the driver and the cable topology follow from it.
- Monitoring and alarms. Worthwhile at fleet scale, but it needs a controller interface, a data owner and a response procedure — see remote monitoring.
Write the control class as numbers a supplier can be held to: switch-on threshold in lux, dimming profile with clock times, standby level in percent, hold time in seconds and the protocol for colour control.
The Classification Table to Send With Your RFQ
Put every line item through the four axes and hand the table to each supplier. It takes an hour and removes most of the guesswork from comparison, because a quotation can only be checked against a requirement you have already written down.
- Space or area name, and the one-line function it must perform.
- Mounting position, height, spacing and aim.
- Location class, and the marking your market requires for that position.
- Power class and voltage — for solar, the worst-month basis rather than the annual average.
- Control class with its settings, and the standard or lux target the area is checked against.
- Maintenance access: how a battery, driver or lamp is replaced without breaking the seal.
- Documentation: which test reports are supplied, and which market each certificate is valid for.
Worked Example: A Mixed-Use Plaza and Car Park
A single development usually needs three or four of the families in the first table. Classifying each line item separately is what stops a path fitting being ordered against a road standard, and it also shows where one supplier can be held to a single energy budget. Here is one site read as five classified line items.
| Line item | Location class | Power class | Control class | Fixture family |
|---|---|---|---|---|
| Access avenue, 15 poles at 8 m | Pole head, wet marking | Off-grid solar, worst-month basis | Time profile, 100 % to 23:00 | Solar street light on pole |
| Car park, 22 poles at 10 m plus 6 wall units | Pole head and wall, wet marking | Solar for poles, mains for wall units | Motion dimming, standby level fixed | Parking lot luminaire and wall units |
| Pedestrian spine, 40 bollards and 12 in-ground uplights | At grade, ground sub-marking required | 24 V separated extra-low voltage | Photocell, zone switching | Bollard and in-ground uplight |
| Hotel facade, 6 wall washers | Wall, 1.2 m or more above grade | Mains | Colour control, protocol fixed | LED wall washer |
| Water feature, 2 submersible fittings | Pool or similar, separated extra-low voltage | 24 V from the landscape zone | Photocell with the zone | LED underwater light |
Read the table as one project rather than five products. Three line items are solar, so they share one energy budget and one layout calculation, while the mains and low-voltage zones carry their own protection and commissioning records. The landscape lighting range and the street and area luminaires are specified from the same schedule, so beam angles, colour temperatures and protocols can be checked against each other before anything is ordered.
Where Classification Goes Wrong
Five habits cause most of the rework we see on outdoor lighting projects. All of them are cheap to fix at specification stage and expensive to fix on site, where the fixture is already mounted and the schedule has already been approved.
- Treating “outdoor rated” as a class. It is a marketing phrase; the evidence is a location marking, or an IP code declared with the family standard.
- Ignoring mounting height. The same fixture can be right on a wall at 2.5 m and wrong on a stake at 200 mm.
- Copying a cable size from a mains schedule. At 12 V or 24 V, voltage drop sets the conductor, and it grows with run length.
- Choosing the control after sizing the battery. Motion dimming changes nightly energy, so autonomy follows the profile.
- Assuming one certificate covers every market. Ask which market each report is valid for, and file the answer with the schedule.
Frequently Asked Questions
What is the difference between a wet location and a damp location?
A damp location is protected from weather but subject to moderate moisture; a wet location is exposed to direct rain, saturation or earth contact. In North America both are defined in NEC Article 100, and the fixture must carry the matching marking. The marking on the label decides, not the description in a catalogue.
Is an IP65 rating the same as a wet location listing?
No. An IP code declares ingress protection under IEC 60529 and is the evidence route in IEC-based markets. In North America the evidence is a listing mark plus a location marking, as NEC 410.10(A) requires for wet locations. Treat IP as comparable technical data, not as a substitute for the marking the local code asks for.
Does a solar street light need the same location class as a grid-connected one?
The luminaire head sits high on a pole, rarely meets ground-level water and is normally specified to IP66 or similar. The parts that do meet the ground are the foundation and any in-ground or submersible landscape fixtures. The energy side is a separate axis: autonomy and control profile decide whether the light runs all night.
Can one classification table cover a project in several countries?
Only in part. Space, power class and control class transfer between markets; the location class does not, because the marking and the code behind it are national. Build the table with one column for “marking required in this market” and fill it per country.
How do I classify a fixture that lights a path and a wall at the same time?
Classify by where it is installed and what surface it must light, then check the optic. A path fixture at grade aimed at a wall is a wet-location ground fixture whose beam must not spill upward, so the numeric limits for upward light and glare belong in the same line item. See our note on glare and light pollution.
Next Step: Send the Classification, Not Just the Fixture List
Send us the area list with mounting positions and heights, the destination market and the control intent. We will return this classification table filled in line by line, the fixture family we would quote, and the documents that support it. Where a figure is not published yet, ask for the specification sheet rather than a guess.
Contact the VOLTIC technical team with your drawing or area list and we will take the schedule from classification to quotation.