Emergency Downlight

Voltage provided to a luminaire by the power supply.

Cycles (frequency) per second.

The operating temperature of a light fitting indicates the safe temperature range in which it can be installed. Exceeding this range can reduce the lifespan. Adhering to specified temperatures ensures optimal performance and longevity.

Lumen Depreciation figures published refer to the L50, L70 or L80 classification system where the number relates to the percentage of light output. So a 30,000hr L70 LED would be expected to have 70% of its rated output at 30,000hrs. LED’s are subject to very small operating temperature parameters and figures quoted are typically at 25°C.

Colour Rendering Index, known as CRI or Ra. The appearance of surface colours when illuminated by light from a given (CRI/Ra) source. Good colour rendering implies similarity of appearance to that under an acceptable light source, such as natural daylight

SDCM, or ‘Standard Deviation of Color Matching,’ is a key metric in evaluating color consistency, especially in LED production. The SDCM value for an LED chip, specified as the initial value, is crucial. A lower SDCM indicates superior color consistency, making it essential for applications requiring accurate and consistent color rendering, such as in commercial, professional, retail, and art settings.

A ‘beam angle,’ also known as ‘beam spread,’ quantifies the spread of light emitted from the source. Measured in degrees, it extends from the ‘Peak Intensity’ of the light source to the point where the measured light diminishes to 50% of the maximum peak intensity.

Class I – Luminaires in this class are electrically insulated and provided with connection with earth.

Class II – Luminaires are designed and constructed so that protection against electric shock does not rely on basic insulation only. This can be achieved by means of reinforced or double insulation. No provision for Earthing is provided.

Class III  – Protection against electric shock relies on the supply of Safety Extra Low Voltage (SELV) and in which voltages higher than those of SELV are not generated (Max.50V ac or below).

IP rating is a global standard showing how resistant a product is against the intrusion of solids and liquids. The first numeral indicates the degree protection against the ingress of solid of
objects, whereas the second numeral refers to the degree of protection against the ingress of
water. The following symbols are appropriate:

• IP20 – Suitable for indoor spaces such as living rooms, entertaining spaces and bedrooms.
• IP44 – Suitable for bathrooms and kitchens, where water may be lightly sprayed.
• IP54 – Suitable for outdoor and bathroom use where water may be lightly sprayed.
• IP65 – Recommended for bathrooms, kitchens and gardens, where there may be splashing of water.

IK ratings are defined as a number from 00 up to 10, indicating the degree of protection against external mechanical impacts. Higher IK Ratings can be particularly useful within warehouses, or for many types of industrial projects.