The specification and ordering questions that stall a first order
Most first orders stop on the same handful of questions. These are the answers we give by email, written down so they can be checked against a standard or a specification sheet.
Standards, optics and installation
The part that decides whether the scheme holds its level.
Why does this site not quote wattage or lumens?
Because a wattage without the calculation behind it is a number looking for a project. The level a space needs, the mounting height and the distribution decide the fixture, and the same space can be lit to the same requirement by different combinations. The build pages state what the specification sheet has to contain, and the sheet for a specific model is sent on request.
Which standard governs a road scheme?
The road lighting standard the authority uses, normally EN 13201 in Europe. The class comes from the road type, the traffic and the conflict areas, and it fixes the level, the uniformity and the glare the scheme may present. The designer then proves the class is reached at the maintenance factor in the contract.
And a sports ground?
EN 12193 in Europe, with the class agreed against the use: training, competition or broadcast. The class sets the maintained level on the playing surface, the uniformity beside it and the glare rating. Over specifying a training ground is common and expensive, so the class should follow the busiest use rather than the best possible one.
What is different about a tunnel?
The threshold zone at the portal is designed against the luminance on the approach, which the designer does not control. That is why a tunnel scheme is specified with a dimming curve and a luminance sensor, and why two identical bores with different portal orientations carry different designs.
What glare figures should I ask for?
For road lighting, the glare rating the standard sets for the class. For sports, the glare rating limit for the viewing direction. For interiors, a UGR limit where people look up at the fixtures. In all three cases the figure comes from the photometric file of the exact model and optic.
How do I know which optic I need?
From the geometry: the mounting height, the distance to the target and the shape of the thing being lit. A wall wants an asymmetric wash, a sign face wants a narrow throw, an aisle wants a narrow beam down it, a bore wants a symmetric or wide asymmetric distribution. The build pages take one case each.
Can you supply a lighting calculation?
Yes, for the layout you provide: pole or mast positions, mounting heights and the surface dimensions. A calculation is what makes two quotations comparable, and it is the document a tender is evaluated on. Without the layout, a calculation is a guess with a graph on it.
What about IP and corrosion ratings?
Both are confirmed on the data sheet for the model, because a rating is a claim that has to be backed by a test. Ask for the figure and the test behind it, and for coastal or polluted sites ask for the corrosion class of the housing and the fixings, which is often the first thing to fail.
Ordering, samples and documents
What happens between the quotation and the first shipment.
What is the minimum order?
One unit per model for a sample, and the range is sold to contractors, authorities and distributors. A scheme is usually quoted as a schedule rather than as a unit price, because the mix of optics is part of the design.
Can the product carry our brand?
Yes. Branding covers the housing marking, the packing and the manual. Artwork approval is part of the schedule, so late artwork moves the delivery date.
How long does a sample take?
Quoted per build. A standard model with existing tooling ships faster than a custom finish, and the sample is where the optic, the fixing and the plug or connection type are confirmed.
What documents come with a shipment?
Commercial invoice, packing list, the data sheet for each line item, the photometric file where one exists, and the certificate file for the market. Ask for the list early, because a missing file at the port costs more than the file.
What about warranty and spare parts?
Terms are supplied with the quotation, because they depend on the build and the destination. The parts that matter in service are the driver, the gasket, the lens and the bracket, and they are quoted with the order rather than sourced later.
One question we cannot answer from here
Which build your space needs. It changes with the requirement, the geometry, the environment and the access, and a supplier who answers it without those four is guessing.
Send the space type, the requirement and the mount. The reply is a build and a specification sheet, which is the answer you can take to a client.
- What to send
- Space, requirement, mount, power
- What comes back
- Build, calculation offer, sheet
- Turnaround
- One reply, from one person
- What it costs
- Nothing, and no account is created
Still stuck on one answer?
Write the question as you would ask a colleague, and the reply comes with the sheet attached.