Technical Terms & Lighting FAQs

Technical information only. This section is general product information, not electrical-design or installation advice. Lighting should be specified and installed by a suitably competent person. Site conditions, wiring, controls and local requirements may mean additional work is necessary.

1. What are lumens?

Lumens (lm) measure the visible light output of a lamp or luminaire. In general, a higher lumen figure means more light output. Lumens are not the same as watts: watts measure electrical power consumption, while lumens describe light output. Modern LEDs can produce high lumen output using substantially less power than older lamp technologies.

2. What is colour temperature?

Colour temperature describes the visual appearance of white light and is measured in kelvin (K). Lower values such as 2200K–2700K appear warmer and more amber; around 3000K is a common warm white; 4000K appears cooler and more neutral. The correct choice depends on the interior, materials, desired atmosphere and task.

3. What is CRI?

CRI, or Colour Rendering Index, is an indication of how naturally colours appear under a light source compared with a reference source. A higher CRI generally means more faithful colour rendering. Premium decorative lighting commonly uses high-CRI LED sources, but the exact value should be checked on the product specification.

4. What is an IP rating?

IP means Ingress Protection. The two-digit code indicates the degree of protection provided by an enclosure against solid objects and water. The first digit relates to solids and the second to water. A higher number does not automatically make a fitting suitable for every environment: the exact installation location and manufacturer instructions must be considered.

For example, IP20 is common for dry indoor areas, while fittings intended for exterior or wet locations usually require a higher water-protection rating. Always use the rating stated by the manufacturer and obtain professional advice for bathrooms, exterior locations and other demanding environments.

5. Bathroom zones

Bathrooms and shower rooms have electrical zones based on proximity to water. The permitted equipment and required ingress protection depend on the precise location, current wiring rules and manufacturer instructions. Do not select a bathroom fitting by IP number alone. A competent electrician should confirm the appropriate fitting and installation method for the exact zone before purchase or installation.

6. Dimming types

Common lighting-control methods include mains phase-cut dimming (such as trailing-edge or leading-edge where supported), DALI, push/switch dimming, 1-10V control and wireless systems such as Casambi. Compatibility is product-specific. A dimmable luminaire does not necessarily work with every dimmer or control system.

Additional control wiring, drivers, interfaces or commissioning may be needed. The electrician, lighting designer or controls specialist should confirm compatibility before installation.

7. Integrated LED and replaceable lamps

Some luminaires contain an integrated LED light source; others use replaceable lamps. The product specification will identify the light source. Where a replaceable lamp is required, check the exact cap type, permitted wattage, physical dimensions and whether the manufacturer recommends LED or another lamp technology.

8. Common lamp caps

Common decorative-lighting lamp caps include E27, E14, G9 and GU10. Other types are also used. Never assume a lamp is compatible solely because the cap fits: check voltage, wattage, dimensions, dimming compatibility and the luminaire manufacturer’s instructions.

9. Are lamps included?

Lamp inclusion varies by manufacturer and product. Where a lamp or light source is included, this should be stated in the product specification. If the listing is unclear, contact 186 Light Ltd before ordering.

10. LED drivers and transformers

Many LED luminaires require a specific driver. Some drivers are integrated; others are remote and may need to be housed in a ceiling void, wall, joinery or another suitable accessible location. Driver type, output, dimming protocol, ventilation and access for future maintenance should be checked before installation.

11. DALI, Casambi and smart-home compatibility

DALI, Casambi and other smart-control systems require compatible luminaires, drivers and control hardware. A product described as dimmable is not automatically compatible with DALI, Casambi, KNX, Lutron, Control4 or another automation platform. Compatibility must be verified against the exact product variant and system design.

12. Outdoor lighting

Outdoor suitability depends on more than IP rating. Consider exposure to driving rain, standing water, salt air, temperature, UV, drainage and mounting orientation. Use only products the manufacturer specifies for the intended exterior environment.

13. Installation responsibility

Electrical installation, alteration and testing should be performed by a suitably competent person. The installer is responsible for confirming the suitability of the electrical supply, protective devices, earthing, wiring, control gear, mounting surface and installation method. Product instructions must be followed.

14. Need specification help?

For product and specification questions, contact 186 Light Ltd through the website customer-service channel or telephone 020 4569 1505. Where the question concerns site wiring, electrical safety or installation compliance, consult a competent electrician or relevant specialist.