LED Maintenance Factors
As with any other lamp/luminaire, when designing with LED/SSL light sources the Lighting Designer must consider the use of an appropriate Maintenance Factor so that the planned lighting scheme gives Maintained Illuminance in accordance with normally specified standards.
Maintenance Factor is determined by deciding what time period the scheme will be serviced (usually taken as a group replacement period).
For LED/SSL it is common to publish/specify lifetime as L70, the time at which the light output drops by 30% to be 70% of initial (L100). If this is combined with other depreciation factors such as the Luminaire Maintenance Factor (LMF allows for dirt), then this would result in a MF of ~0.60 in calculations if the L70 time period is used. A MF of 0.60 will lead to an uneconomical amount of initial over-design. It is common to use 0.80 for indoor projects (for T26 and T16), and 0.70 for general outdoor projects (for MH, can be higher for HPS).
If a comparable MF for SSL/LED is to be used then it would be more appropriate to use burning hours at L90 or L80 in combination with LMF. These values should be available from suppliers, and the maintenance period declared in the design documents (as with any other light source).
http://www.iesanz.org/_r796/media/system/attrib/file/1229/LED Light Sources and Luminaires -Design Factors %5BIESANZ Position Statement%5D.pdf
Binless LED Tips
During production, LEDs vary in colour, luminous flux, and forward voltage. Since the differences are significant, LEDs are measured and delivered to the market in subclasses, or bins. Binning makes it possible to select LEDs that conform to stated specifications -- for instance, to select LEDs for traffic signals with the specific colour required to meet the European standard.
TIP: One important goal for lighting fixture manufacturers is to select bins of LEDs in such a way as to minimize differences in colour that might be visible from fixture to fixture or from production run to production run.
TIP: So the benefit of Binless LED modules is that binning has been taken care of. That is, you won't have colour inconsistency issues or voltage differences with the LED modules.
This video helps to explain :
http://www.youtube.com/v/sZQg5Kzotes (courtesy of Philips Lighting)
TIP: Binless LED's have been made possible through advanced phosphor technology which results in a more consistent finished colour.
TIP: The language may change; but the meaning is the same. "Binless" or "Freedom from Binning" are two terms that are used to describe the same process.
LED Life Evaluation Tips
LEDs are known for their long life. Claims such as 50,000 hours are not uncommon. But how do we evaluate the life of an LED compared to the traditional light sources.
TIP: The life of incandescent, fluorescent, and high intensity discharge lamps is expressed as rated life which is when 50% of a large batch of lamps has failed when operated under controlled conditions.
TIP: LEDs are different; they don't fail abruptly like traditional sources. LEDs tend to slowly fade away and therefore can last a long time but produce little light.
TIP: The life of an LED is based on the decline of the light over a period of time. This is also called lumen maintenance.
TIP: We now have new terms like L70 and L50. Lumen maintenance is often specified as L50, L70, L80. The number is the percentage of light output remaining.
TIP: L70 is commonly used to evaluate the life of an LED because the human eye cannot detect a change in light output until it has been reduced by 30%
TIP: B50 is also used to describe the life of an LED. B50 indicates no more than 50% of a sample of LEDs would be expected to have their light output drop below a target lumen maintenance level. B10 would mean no more than 10% drop below the target level.
TIP: The life of an LED is commonly expressed as (B50,L70). This is when 50% of a large group of identical lamps are below 70% of initial lumens.
TIP: Life also is impacted by electrical and thermal conditions determined by the luminaire and system design rather than the properties of the LED.
TIP: At this time there is no approved Australian standard for reporting life time or lumen depreciation data for LED lamp sources. However the LM-80 has been adopted by most manufacturers. LM-80 is the approved (IESNA) method of measuring lumen maintenance of LED light sources.
TIP: Again in the absence of an Australian LED Luminaire Standard, validation of LED luminaire performance is best covered by the process of the Lighting Council SSL Quality Scheme; where test reports in the form similar to that required by LM-79 must be provided to The Lighting Council from independent test laboratories that demonstrate the product performance. Upon approval, The Lighting Council then issues the labels for each of the products listed, which are evidence of their certification.
T5 Energy Saving Tips
T5 Tubes have always been presented as an energy saving option to traditional T8 lamps. However in recent times we have seen the emergence of the T5 Energy Saving tube which offers even greater savings.
TIP: The Energy Saving versions have reduced wattage when compared to the original T5 lamps.
TIP: T5 28watt (HE) = T5 25watt Energy Saving, T5 35 watt(HE) = T5 32watt Energy Saving, T5 49watt(HO) = T5 45watt Energy Saving, T5 54watt (HO) = T5 50watt Energy Saving, T5 80watt(HO) = T5 73watt Energy Saving.
TIP: The T5 Energy Saving lamp has the same lumen output, lumen maintenance and life as the original T5 lamp. Manufactures' data should be used to determine actual values.
TIP: It is not an automatic energy saving result. The ballast plays an important part in the outcome.
TIP: To achieve the 10% Energy Savings the lamp must be operated on a Current Controlled Ballast.
TIP: When operated on a Power Controlled Ballast the energy saving is zero; however the lumen output is increased to 110%.
TIP: The Energy Saving lamp can be used on both fixed output and dimmable ballasts.
TIP: Replacing an original T5 lamp with a T5 Energy Saver lamp will not necessarily deliver an energy saving outcome unless it used on the correct ballast.
TLEDs are LED tubes designed to replace conventional fluorescent T8 lamps. We need to be aware of how they perform if we are to make a true comparison between old and new technology.
TIP: While these are retrofit lamps they will work on magnetic ballast only (not electronic). When operating on magnetic ballast the starter needs to be replaced with a fuse which looks and fits like a starter.
TIP: To gain maximum efficiency it may be wise to remove the ballast and operate the lamp directly on 240 volt supply. In these situations the luminaire must carry a warning of the dangers of replacing the TLED with a conventional T8 tube and the fitting must have a fuse for protection.
TIP: The 10 watt LED replaces an 18watt and 19watt replaces a 36watt tube .
TIP: The efficacy is about the same. TLED is 80 lumens per watt and T8 is closer to 90 lumens per watt.
TIP: When retrofitting you may not get the same amount of light. A 36watt T8 will deliver 3250 lumens. The 19watt LED replacement only 1650 lumens.
TIP: The TLED has it is own inbuilt reflector. The T8 relies on the reflector in the luminaire to direct light onto the working plane. The other consideration is how many lamp lumens reach the working plane. A highly efficient optical system may work best with conventional lamps.
TIP: The life of a TLED IS 40,000 hours. A T8 is 15000 hours. Be aware the TLED life is based on 70% of initial lamp lumens and the T8 is based on 50% mortality. There are special T8 lamps (Extreme) that have a life of 67000 hours and are a fraction of the cost.
TIP: The TLED will operate at a lower ambient temperature (-30C to +45C) than the T8. The maximum output of a T8 is achieved at 25 degrees C with reduction as the ambient temperature changes. This makes the TLED suitable for cold environments including cool rooms.
TIP: Safety is an important consideration. There is a risk of electric shock with some products. TLED has an inbuilt safety protection to prevent this happening.
TIP: TLED is like any other lamp; there are benefits that recommend it for use in many applications. However, we need to apply the same scrutiny that we apply to all lamps.
The Building Code of Australia (BCA) is a mandatory document setting the technical provisions for the design and construction of buildings across Australia.
TIP: Section J6 addresses energy efficiency in buildings and specifically, Artificial Light and Power.
The objective is to minimise power consumption of lighting installations through the application of energy smart practices and the employment of efficient products.
TIP: Table J6.2a provides maximum Illumination Power Density (IPD) expressed as watts per square metre for specific applications. While the lighting levels must comply with Australian Standards (AS/NZS1680) the IPD can be acheived through the use of high efficacy light sources, electronic control gear and efficient luminaires.
TIPS: Concessions to the specified values of IPD (watts/m2) in Table J6.a can be obtained by using intelligent lighting control including timers, motion detectors, dimming and daylight sensors.
TIPS: Pierlite has met the challenges of Section J6 of the BCA by providing optimum lighting solutions using state of the art products that ensure compliance with BCA. Further information is available on the Pierlite website: www.pierlite.com
The Green Star environmental rating system for buildings was developed by the Green Building Council of Australia (GBCA). Green Star is Australia's first comprehensive rating system for evaluating the environmental design and performance of Australian Buildings based on a number of criteria including energy and water efficiency, indoor environment quality and resource conservation.
TIP: Green Star Certified ratings are: 4 Star Best Practice, 5 Star Australian Excellence and 6 Star World Leadership.
TIP: Credits are available for good lighting practice based on the use of energy efficient measures. The practices include use of electronic gear, maintaining illuminance levels within the recommendations of AS/NZS1680, achieving minimum power density and office zoning.
TIP: Although the Green Star certification requires a formal process, design assistance is available through your local Pierlite office
High frequency (HF) electronic control gear for fluorescent lamps
It can be argued that HF electronic control gear is indeed a complex technology when compared to the traditional magnetic variety. With the reality of escalating energy costs and the need to create sustainable energy solutions, it is understandable why the development of HF technology has now taken electronic control gear to a level of sophistication, particularly when it comes to dimming and energy control of fluorescent lamps. Courtesy of Tridonic, an informative reference manual has been prepared detailing wiring and installation guides covering both fixed output and dimmable electronic control gear.
Select this link for more information
LED’S! Do they measure up to the claims?
LED’s have transformed the way we think about lighting, but are they all that they say they are?
If you see a claim that is too good to be true it probably is so here are some quick checks to consider before you spend your well-earned cash:
• Is the product SSL certified? – Independent certification takes all the guess work from your decision.
• Does the product conform to EMC regulations? – get this wrong and you introduce serious interferences for TV’s phone and electronic health services such as pacemakers
• LED’s that perform equally to traditional light sources do exist, but unless they are producing the same lumen output they are more than likely not providing and equivalent performance.
| Lamp Type
| High Pressure Sodium
| Metal Halide
BEFORE YOU DECIDE
• If you see a claim that states “equal to an equivalent HID product” simply ask for the lumen output and if they are not equal challenge the claim.
• Don’t forget to sight the independent certification and the EMC compliance.
EMC – what you should know?
EMC is the control of electromagnetic interference and the compatibility of electrical and electronic equipment. Lighting operating within the frequency spectrum of 9 kHz to 30 MHz has limits placed on electromagnetic emissions as specified in AS/NZS CISPR 15: 2006
There are two types of electromagnetic emissions.
CONDUCTED - where electrical noise is transmitted back through the wiring .When the specified limits are breached this may affect equipment within the installation.
• The Control signal may be activated or cancelled
• Medical equipment could shut down or record incorrect data
• TV and radio interference
RADIATED - where noise is transmitted through air. When specified limits are breached this may have the following impact.
• Effect communication signals allocated to TV, Radio or Traffic control.
• Interfere with medical devices such as a pacemakers or hearing aids.
The RCM is a new acknowledgment of EMC and safety compliance, this will replace the C Tick now used to demonstrate compliance.