On this site, the same LED high bay lights the circulation aisle, the component store and the final inspection station. The inspector works with a desk lamp he brought in himself. The installation is recent, uniform, and unsuited to two of its three uses.
Why a single level costs a lot and lights badly
Applying a single illuminance to a whole workshop produces two effects at once. Circulation and storage areas receive far more light than necessary, which weighs on the installed power and on the bill. Demanding workstations, on the contrary, stay below the expected value, because the level chosen is a compromise set on the average of the building.
The result can be seen on the ground: personal lamps at inspection stations, and aisles lit like assembly areas. Zoning corrects both gaps with the same intervention.
Zoning the workshop: workstations, circulation, storage, quality control
Zoning consists of dividing the workshop according to the visual task actually performed, not according to the walls. A single bay can contain three zones: an assembly station, an area for setting down parts and a service aisle.
Four families cover most workshops: production and assembly stations, circulation and handling areas, storage areas, and inspection or rework stations. Each calls for its own level, its own uniformity and sometimes its own colour rendering.
The division is done on site, plan in hand, by asking the area managers. Two questions are usually enough: what is the smallest thing the operator must make out at this station, and how many hours a day does he stay there. An area where people pass through for a few minutes per hour and an area where they assemble for eight hours straight are not treated in the same way, even if they adjoin.
What the EN 12464-1 standard requires according to the task
Area or task | Maintained illuminance | UGR limit | Colour rendering |
|---|---|---|---|
Traffic routes and corridors | 100 lux | 28 | Ra ≥ 40 |
Storage area with occasional occupancy | 100 lux | 25 | Ra ≥ 60 |
Storage area with permanent occupancy | 200 lux | 25 | Ra ≥ 60 |
Rough assembly | 200 lux | 25 | Ra ≥ 80 |
Medium assembly | 300 lux | 25 | Ra ≥ 80 |
Fine assembly | 500 lux | 22 | Ra ≥ 80 |
Precision assembly | 750 lux | 19 | Ra ≥ 80 |
Colour inspection | 1000 lux | 16 | Ra ≥ 90 |
These values are maintained illuminances, assessed on the task area. The standard adds a minimum uniformity of 0.60 on this area and 0.40 on the immediate surrounding band, at least 0.5 metre wide around the task.
General lighting and supplementary lighting at the workstation
Two strategies are combined. General lighting provides the base level over the whole area, sized for the most common zone. Supplementary lighting, fixed to the workstation or the machine, raises the level locally where the task requires it.
This combination almost always costs less than raising the general level. It does, however, impose one rule: the contrast between the brightly lit task area and its immediate surroundings must remain limited, otherwise the eye wears itself out constantly adapting. The standard governs this gap through the illuminance scale for the surrounding area.
Supplementary lighting also raises an operating question. A workstation luminaire plugged into a socket, adjustable at will, ends up being moved, unhooked or replaced by the first model to hand. Supplementary lighting built into the workstation, powered and fixed with it, stays in place and keeps its photometric characteristics. The extra cost of integration is recovered over the life of the line.
Cast shadows and lighting parts in three dimensions
A mechanical part is inspected in three dimensions, not flat. Lighting from a single direction creates hard shadows that hide a defect on one side and reveal it on the other. Lighting that is too diffuse flattens relief and makes scratches invisible.
The compromise is set by the number of lighting directions and by the size of the sources. In practice, two linear luminaires placed on either side of the workstation give a better result than a single powerful fitting directly overhead. At welding, painting or surface inspection stations, this setting is handled luminaire by luminaire.
Mounting height, dust and maintenance plan
The height under the roof frame governs the choice of optic and the number of light points. The greater the height, the narrower the beam must be, and the more sensitive uniformity becomes to obstacles: overhead cranes, ducts, racks, partition walls.
The environment then weighs on durability. A machining workshop with oil mist, a woodworking shop with fine dust or a cutting workshop with spatter call for neither the same protection rating nor the same cleaning interval. This interval goes directly into the maintenance factor of the calculation: an optimistic cleaning plan leads to an undersized installation.
Checking the zoning by simulation before the works
Zoning is validated before ordering. A photometric study gives, for each zone, the average illuminance, the uniformity and the UGR, and shows the transitions between zones in false colours. This is where abrupt breaks are spotted between an aisle at 100 lux and a workstation at 750 lux, which force the eye to adapt constantly.
The simulation also settles the split between general and supplementary lighting. It puts a figure on the number of fittings saved by lowering the general level, and on the cost of the supplementary luminaires that compensate for it. The benchmarks that apply to each type of room are detailed on our page on the compliance of lighting installations, and all our lighting solutions by sector of activity cover the most common workshop configurations.
On the equipment side, LED luminaires for production areas cover general lighting, while workshop luminaires handle the workstations that need a higher level.
To have your workshop zoned and the levels validated before the works, request a visit from the contact page.
