Welcome to The LED Specialist blog. We feel that we have a responsibility to our viewers to explain the complicated LED market in order to ensure that the correct products are purchased and that cheap inferior products are not purchased which diminishes the energy saving capabilities of LED lighting.
Thursday, 29 May 2014
Tuesday, 27 May 2014
More from Philips' Spring Collection: CoreLine Wall-mounted LED Luminaire
Philips CoreLine LED |
Benefits:
• Up to 55% energy savings compared with luminaires with PL-C
lamps
• Direct replacement for traditional wall-mounted luminaires
• Complete range covering all application requirements in one product
(light levels, IP65, IK10, certified emergency lighting, built-in controls)
Features:
• Unobtrusive design
• Three lumen packages replacing traditional wall-mounted luminaires
with 1x18 W / 2x18 W / 2x26 W PL-C
• Water- and vandal-proof as standard
• Phase-cut dimming as standard
• Frosted diffuser ensuring homogeneous light effect and visual
• Optional emergency lighting
• Optional on/off movement detection or programmed 100%-10%-0%
corridor dimming functionality
Application:
• Corridors
• Staircases
• Public entrance areas
• Bathrooms
• Emergency exits
• Parking garages
• Outdoor safety lighting
Tuesday, 20 May 2014
Philips Unveil Their Spring Collection: iColor Flex gen2
Philip iColor Flex MX gen2 |
All iColor Flex gen2 nodes on the flexible strand is individually controllable, providing the ultimate flexibility in lighting design and ambiance. The flexible strings fit nearly any architecture meaning they are suitable for all kinds of application. The flexibility offered by iColor Flex gen2 luminaires is current unrivalled, enabling users to customize node count and spacing. In comparison to their predecessor, iColor Flex gen1, the gen2 luminaires offer twice the brightness using the same power level.
Philips iColor Flex LMX gen2 |
These luminaires offer superior light output of up to 2.6 candelas. They have multiple lens options, including both clear and translucent domes. The strands can be mounted directly to a surface much like traditional string lights. The iColor Flex gen2 luminaires are compatible with most industry leading controls including Philips' Video System Manager Pro, Light System Manager, and iPlayer 3.
The iColor Flex gen2 comes in two options: iColor Flex MX gen2 and iColor Flex LMX gen2. Below is a table of thier specifications provided by Philips lighting.
Philips iColor Flex LMX gen2 |
Philips iColor Flex MX gen2 |
Tuesday, 13 May 2014
Philips unveil their Sensor-Ready system for connected office lighting
Philips’ Sensor-Ready system uses LEDs which are powered
over Ethernet; the system provides building owners and facility managers a
plethora of useful data about their properties.
After the positive feedback Philips received about their
Li-Fi system for retail stores, the Dutch conglomerate unveiled this clever
indoor lighting solution for the office.
At the Light +Building show in Frankfurt, Germany, Philips
proudly displayed their connected office -lighting system. The system’s LEDs
are wired up to the buildings IT network, power is provided by the Ethernet which
produces just enough juice for low power LEDs, the system can also include
sensors for monitoring humidity and temperature, as well as for judging when a
room is occupied or not.
Similar to Li-Fi, the lights can also act as a positioning
grid helping people navigate the office layout. The lights again are able to communicate
through a downloadable smartphone app, the fixtures can track the user’s
whereabouts and help recommend for example the nearest vacant meeting room.
Using the app, staff are able to easily adjust the lighting and temperature of
the room they’re in via Philips’ office lighting app.
This innovative system enables building owners and facility
managers to measure occupancy levels and energy usage, Philips’ software
displays these is an easy to read format ensuring consumers benefit from all
aspects of the connected lighting system. Using information collected by the
app, managers and owners can easily decide when certain area need to be heated,
how often specific rooms need cleaning and which rooms need to be lit and when.
When asked about the benefits of this lighting system,
Philips spokesman Menno Kleingeld said: “It’s gathering a large database of
information for various fixtures for facility managers, to make their life
easier.” He went on to discuss how in addition to the energy saving benefits,
the system may also provide a security benefit by sensing when someone is in a
room which should not be occupied.
For more information on this lighting system or for any
further information on LED lighting products visit our website http://theledspecialist.co.uk/ or call the office to speak to one of our highly skilled sales team 0118 939 3218
Thursday, 8 May 2014
Tuesday, 6 May 2014
A Guide To The Specification of LED Lighting Products- Part 4 of 4
Luminaire
Manufacturers Design Data
When evaluating LED luminaire performance claims it is important to compare a standardised set of quality criteria measured in compliance with the appropriate standard.
When evaluating LED luminaire performance claims it is important to compare a standardised set of quality criteria measured in compliance with the appropriate standard.
Luminaire
Manufacturers Design Data
These
quality criteria are designed to ensure that performance claims can be matched
against traceable data.
This
data is summarised below:
1) Rated input power (in W)
2)
Rated luminous flux (in lm)
3) LED luminaire efficacy (in lm/W)
4)
Luminous intensity distribution
5)
Photometric code
5a) Correlated Colour Temperature (CCT in
K)
5b) Rated
Colour Rendering Index (CRI)
5c)
Rated chromaticity co-ordinate values (initial and maintained)
5d)
Maintained Luminous Flux
6) Rated life (in h) of the LED module and the
associated rated lumen maintenance (Lx)
7) Failure fraction (Fy),
corresponding to the rated life of the LED module in the luminaire
8) Ambient temperature (ta) luminaire
9) Power Factor
10) Intensity Distribution
11) Drive Current
12) Optical Risk
Product
Types; Safety Standards and Performance Standards
Product Type
|
Safety Standard
|
Performance Standard
|
Self-ballasted LED lamps for general lighting
services >50v
|
IEC
62560 Edition 1Publication
expected 2010
|
IEC
62612/PAS Publicly Available
Specification
|
Control
gear
for LED modules
|
IEC
61347-2-13 Published 2006
|
IEC 62384 Published 2006
|
LED
modules for general lighting
|
IEC
62031 Edition 1 Publication 2008
|
IEC/PAS 62717 Published 2011
|
LED
luminaires
|
IEC
60598-1
|
IEC/PAS 62722-2-1 Ed. 1: Luminaire
performance – Part 2-1: Particular requirements for LED
|
LEDs
and LED modules
|
ICE
TS 62504 Terms and Definitions for LEDs and LED modules in general lighting
|
|
CIE
technical
committees
|
TC2-46
CIE/ISO
Standards on LED intensity measurements
|
|
|
TC2-50
Measurement of
the optical properties of LED clusters and arrays
|
|
|
TC2-58
Measurement of
LED radiance and luminance
|
|
|
TC2-63
Optical measurement of
High-Power LEDs
|
|
|
TC2-64
High speed testing
methods for LEDs
|
Thursday, 1 May 2014
A Guide To The Specification of LED Lighting Products- Part 3 of 4
Quality
Criteria
The IEC has developed a list of performance requirements for both LED modules and LED luminaires. These provide a set of quality criteria related to the initial specifications of a product and a standardised description on how to measure these quality criteria.
Following this proposed criteria allows you to easily compare manufacturers claims of initial specifications of LED modules and luminaires.
Quality Criteria- Rated Input Power
The rated input power shows the amount of energy consumed by a luminaire, including its power supply.
It is expressed in watts.
The IEC has developed a list of performance requirements for both LED modules and LED luminaires. These provide a set of quality criteria related to the initial specifications of a product and a standardised description on how to measure these quality criteria.
Following this proposed criteria allows you to easily compare manufacturers claims of initial specifications of LED modules and luminaires.
Quality Criteria- Rated Input Power
The rated input power shows the amount of energy consumed by a luminaire, including its power supply.
It is expressed in watts.
Quality
Criteria- Rated Luminous Flux
This is the light emitted by the luminaire which is expressed in lumens.
For traditional luminaires it is usual that Relative values are measured and multiplied by the lamp flux.
For LED luminaires it is recommended that Absolute photometric values are used. Absolute photometry results in a LOR=1.
Quality
Criteria- Correlated Colour Temperature (CCT)
Although white light is a mixture of colours, not all whites are the same since they depend on their constituent colours.
So a white with a higher proportion of red will appear warmer and a white with a higher proportion of blue will appear cooler.
In order to classify the different types of white light, the concept of colour temperature is applied which is described as the colour impression of a perfect black-body radiator at certain temperatures.
This concept can be best explained with the help of familiar thermal radiators like the filament of an incandescent lamp or an iron bar.
When these materials are heated to a temperature of 1000k their colour appearance will be red, at 2000-3000k they will look yellow white, at 4000k neutral white and at 5000-7000k cool white.
The higher the colour temperature, the cooler the perception of the white light becomes.
It is expressed in kelvin.
The initial CCT value classification for the photometric code can be obtained by taking the initial CCT value divided by 100.
Quality
Criteria- Rated Colour Rendering Index (CRI)
Although light source may have the same colour appearance, this doesn’t necessarily mean that coloured surfaces will look the same under them.
Two lights that seem to have the same white colour appearance may be the result of different blends of wavelengths.
As a result a given material may appear differently since the surface may not reflect the constituent wavelengths by the same extent.
Its colour appearance will change when it is exposed to one or other light. So, colour rendering is an important criterion when selecting light sources for lighting application solutions.
With new LED technology coming in, with a narrow spectrum, the CRI index is not in all circumstances giving a fair representation of the colour appearance.
New definitions and methods for measuring are currently under development in CIE.
The initial CRI value classification for the photometric code can be obtained by using the following intervals:
Code
|
CRI
Range
|
Colour Rendering Properties
|
6
|
57-66
|
Poor
|
7
|
67-76
|
Moderate
|
8
|
77-86
|
Good
|
9
|
87-100
|
Excellent
|
Quality
Criteria- Lumen Maintenance Code
As the typical life of a LED luminaire is very long, it is time-consuming to measure the actual lumen reduction over life.
Also the actual LED behaviour with regard to lumen-maintenance may differ considerably by type and manufacturer.
It is not possible to express the lumen-maintenance of all LEDs in simple mathematical relations. A fast initial decrease in lumen output does not automatically imply that a particular LED will not make its rated life.
In order to validate a life time claim an extrapolation of test data is needed. In the IEC a general method of projecting measurement data beyond limited test time is under consideration.
Quality
Control- Lumen Maintenance Code
In the US an extrapolation based on LM-80 test data be described in IES TM-21. Instead of life time validation, the IEC/PAS has opted for lumen maintenance codes at a defined finite test time.
Therefore the code number does not imply a prediction of achievable life time. The maintained luminous flux is measured at 25% of rated life time up to a maximum of 6,000 hours and expressed as a percentage of the initial value.
The maintained value determines the lumen maintenance code.
Lumen
Maintenance
(%)
|
Code
|
>90
|
9
|
>80
|
8
|
>70
|
7
|
Quality
Control- Photometric Code
A six digit photometric code that displays the important ‘quality of light’ parameters.
Quality
Control- Rated Life (in h) of the LED Module and the Associated Rated Lumen
Maintenance
The length of time expressed in hours, during which a population of LED modules provides more than the claimed percentage (x) of the initial luminous flux always published in combination with the failure fraction.
The recommended series of values for (x) is 70, 80, 90.
Quality
Control- Failure Fraction (Fy),
corresponding to the rated life of the LED module in the luminaire
The percentage (y) of a number of LED modules of the same type at their rated life that have failed.
This failure fraction expresses the combined effect of all componenets of a module including mechanical, as far as the light output is concerned.
The recommended series of values for (y) is 10,50.
Quality
Control- Ambient Temperature (ta) for a Luminaire
The ambient temperature around the luminaire related to the specified performance.
For a given performance claim the ambient temperature (ta) is a fixed value.
It is possible to specify performance claims at different ambient temperatures.
If the LED luminaire is to be used at an ambient temperature different to that at which it was tested, correction factors will need to be applied to the performance criteria.
It is expressed in degrees Celsius.
Quality
Control- Power Factor
The power factor should be clearly stated in all cases.
Although product standards may not require this below 26w, it should be noted that some clients, and in particular contractors and local authorities working with un-metered supplies, will require power factor correction of 0.85 or better.
Quality Control- Intensity Distribution
Photometric data is available in two formats.
Absolute Photometry does not require the use of a separate lumen output for the light source.
Relative Photometry requires the LED package flux to be quoted.
Both methods produce the same result. For LED luminaires Absolute photometry shall be used.
Absolute
photometry of LED luminaires should
be conducted according to IES LM-79-08 Photometric Measurements of Solid-State
Lighting Products.
Relative
photometry should be conducted according to EN13032-1 (2004) Light and lighting
Measurement and presentation of photometric data of lamps and luminaires-
Part1: Measurement and file format.
These standards contain advice on measurement uncertainty.
Photometric results that are calculated by deviation from the tested sample by the use, for example of higher or lower drive currents or dies from bins other than the bin used for the tested device are to be clearly identified as such.
Correction factors used are to be provided with the results.
Quality
Control- Drive Current
For proper operation, the power supply and electronics must provide a well-controlled DC drive current. Drive current affects LED operating temperature a thus life and output.
Normally around 350mA is quoted but this can be higher. The higher the LED is driven the brighter it will be but it may have a shorter operation lifetime and be less efficient. Some of the new multi die LEDs are designed to operate and perform at higher drive currents.
Declaration of the drive current is important when remote drivers are used.
Quality
Control- Optical Risk
The Control of Artificial Optical Radiation at Work Regulations 2010 apply to light emitted from all artificial light emitted from all artificial light sources including LEDs.
These regulations require employers to protect the eyes and skin of workers from exposure to hazardous sources of artificial optical radiation.
Exposure limits defined in the standard EN-62471 are in European regulation (directive 2006/25/CE). These are a combination of source power and exposure time.
Exposure limits defined in the standard EN-62471 are in European regulation (directive 2006/25/CE). These are a combination of source power and exposure time.
When light sources are placed in a luminaire, the Risk Group classification can change due to the optics used in the luminaire.
Risk
Group 0
|
Exempt
|
Risk Group 1
|
Low
|
Risk Group 2
|
Moderate
|
Risk Group 3
|
High
|
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