Why Do LED Lights Fail Early

Do LED Lights offer a high life time of 50,000 Hrs as in manufacturer's catalogs? There are some factors causing LED Luminaries ending their life in an unexpected way before the actual life time offered by the manufacturer.

Integral parts of an LED lights are LED chip, LED Driver, and Heat Sink (which is generally LED fixture body), wires and harness.Another important material is the thermal compound which is applied as an interfacing material between LED chip thermal exchange pad and heat sink.

There are certain criteria in selecting above components and integrating them to a product resulting in a high performance and highly reliable product.

Why do LED luminaries fail early

Power supply variations:  

         

          LED lights are sensitive to fluctuations and surges in power supply which will cause LED driver failure. The best thing to prevent this to enable surge protection for LED drivers while manufacturing them.Also external surge protection devices can be installed to ensure higher protection. LED drivers also should operate in a wide range of input voltages say 85-320VAc. Before purchasing the LED drivers, read the manufacturer's product manual to ensure that basic protection is enabled.

Thermal Management

      This is an important factor which should be given proper attention while assembling LED luminaries. Thermal interfacing material used should be adequate to conduct the heat from LED junction to the surface of heat sink so that the junction temperature of the LED chip specified by the manufacturer should be with in the permissible limit. Thermal characteristics of the thermal compound should be inline with the LED chip manufacturer's specifications, following the same will give a good life time. If a manufacturer is failing to use a thermal compound with adequate thermal conductivity, causing early burn out of LED chips so that the luminary life will be drastically lowered.

An adequate hear sink with area of dissipation designed according to the LED chip manufacturer's specification is also mandatory.

Manufacturing: ESD sensitive devices

                  LEDs are sensitive to electrostatic charges. LED luminaries should be manufactured in ESD proof environments. Proper measures should be provided to handle the luminaries to protect  them from static charge this will ensure a high life to luminaries. Improper assembling setups will cause permanent ESD damages to luminaries. Always refer the ESD guidelines before handling LED components. 

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LED LIGHTING MYTHS : CUSTOMER'S POINT OF VIEW

LED lighting products are gaining  popularity among common people these days also the chances of choosing an undesirable product is more than ever. For choosing a desirable product, the following FAQs will be useful.

1. Choose higher lumen: Don't compare the power of the luminaries compare the lumen output. This will help you achieve more performance in same power compared to the luminary having less lumen output, sometimes you can reduce the no. of luminaries also.Different make of LED luminaries having same power may deliver different lumen outputs 

2. Efficiency> 85%: LED Driver: choose a driver with higher efficiency. We need at least 85% efficiency to achieve the power savings offered by the LED technology. 

Which means a costlier LED luminary with lower efficiency driver may consume the same power of standard fluorescent luminary having higher efficiency driver. How ever higher the efficiency higher will be the cost of the luminary.

3. Power factor>0.9  : Power factor of the LED driver should be greater than 0.9 and THD< 15  to avoid more loading on the electrical grid and on your generators or inverters. With higher power factor you can connect more load to the existing generator or inverter compared to a lower PF one.

SEMILON LED LIGHTING; BEST APPLICATION AREAS

Last few years Indian LED market is growing exponentially and LED will hold 80% of the Lighting market share by 2020. Nowadays most of the customers choose LED lighting products for their lighting applications especially home, outdoor, commercial and industrial application.

How will we find best suited LED lighting application. This article will help you to find the application areas and LED fixtures that will give you better savings, performance and better ROI.

Following application areas to be chosen for achieving maximum advantages from LED lighting

• Areas which need more than 10 Hrs lighting/Day like hospitals, retail shops, industries.

                           

                                                           Multi-specialty hospitals, retail stores, industries are best application areas of LED lighting where the light engines run more than 10 Hrs a day. It give chance of achieving ROI point earlier. LED light fixtures manufactured through standard process and using quality material will give a life of 50K hrs and there is no need of replacement of another fixture.The ROI can be achieved in 10-12 months if the customer use this light for 15-20 Hrs.

• As a replacement to metal-halide, sodium vapor and halogen lamps.

 Halogen and metal halide lamps use large reflectors for directing light towards the work plane, this will cause of 45% light loss and light pollution. LED lights with 70% less power can replace conventional halogen lamps giving more cost savings and faster ROI. Secondary optics ensures uniform distribution through out the work plane reducing glare and light pollution.

• When the input power is drawn from solar systems.  

                                               

                                                     LED light engines consume less power compared to conventional light fittings. You can reduce the no. of solar panels, which contribute the majority of cost of solar power plants, since the total connected load will be reduced by installing LED lights. Also you can connect to a inverter having lesser VA rating reducing initial investment. 

Other areas of lighting

      Outdoor lighting area, architectural lighting where extremely small and high intensity lighting fixtures are needed. Lens of LED lights makes it perfect for highlighting the building structures, reducing light pollution, glare, giving an option to set various beam angle (10 to 90 Degree), and perfect light distribution.

• For applications where variable color rendering and color temperature are needed

                                                                  LED lights are available in various color temperature and CRI. LEDs can reproduce almost all colors of color spectrum. Making it a perfect solution for various applications like stage lighting, aquarium lighting, grow lighting, architectural lighting, spot lighting etc.

• Comparability with digital automation or digitally addressed interfaces are used

Extremely compatible for indirect lighting or mood lighting: LEDs can be dimmed up to 0% from 100% to maximize energy savings, also the customer can choose from different lighting patterns and mood lighting.For this you need a automatic or manual dimmer, connected with a dimming compatible LED driver. Dimming also increases life of LEDs since it gives an option for LEDs to work in a lower junction temperature.

SEMILON. LED LIGHTING ADVANTAGES

Is it really a wise decision to invest on LED lighting than on a conventional light engine? Here we will discuss some relevant points that will throw light on our pathway to LED lighting.


Life of LED

It is calculated that LED chips will give a long life up to 150000 hrs compared to 10,000 hrs of CFL and 1000 Hrs of Incandescent bulbs. But the life of LED s is dependent on the make of LED, thermal management of the LED fixture and LED driver life. If anything of above said is not matching the criteria for good performance of LED chips and according to the specs given by the manufacturer, the LED's life drastically reduce even if it offer a very long life in the datasheets.

Long life of the LED light engines means you don't need to replace a LED light for 17 Hrs even if you are using it for 24 Hrs a day. So there is no burden of replacing the damaged products and you can save money buying new products for replacing damaged one and also maintenance costs will be very low.

Environmental friendly

LEDs uses 50-70% less power compared to conventional luminaries. One should be very careful in choosing LED light engines to achieve the above said. Since the LEDs are available offering 30-160 Lm/W, the customer should select atleast 105 Lm/W LED to achieve an equivalent performance of CFLs  which offer 60 Lm/W . Since the LEDs are directional and radiating in a narrow beam angle, say 120 Degree it will create more impact on performance compared to conventional fittings which is radiating in 360 Degree where there is a loss caused by the reflector or shade we use integrated with the light engines.

Customers should also choose a good quality driver having higher energy efficiency and power factor, built in with long lasting electronic components to enjoy the max power saving and long life.

Moreover LEDs contains no toxic substances like Mercury which is there in CFLs, disposal of these light engines have a lesser impact on the environment.

Other benefits are 

• Shock  proof: LED lights are shock resistant compared to the conventional light fittings and chance of damage is very less.
• Dimming compatibility: LED lights can be coupled with ambient light sensor or manual /automatic dimmer to achieve even more power saving.
• Radiate less heat: Contains no infrared and ultraviolet radiations.

SEMILON, LED LIGHTING FACTS

What are the facts we need to focus before purchasing a LED lighting product. In this blog you can read some of the most important lighting facts customers need to know before taking a decision to choose a product.

Luminous efficacy

Do you know that High Bright LEDs offer different lument output for same power? Yes LEDs are available in the market that offer 30-160 Lm/W(Lumen /Watt). Lm/W is commonly reffered to the term Luminous eefficacy.This means that for the same power two LEDs having different efficacies can offer different lumen output. 

Customers  may not be aware of this fact. Normally LED lighting products in the market are compared on the basis of output power of the product.  This may mislead them to choose a product with lowest price comapred to high priced products so that the products choosen may not be delivering sufficient amount of light customer need, since the price of the LED lighting products generally depends on light out put of the product.

So it is a good thing to compare price/lumen than price/watt when we decide to purchse a LED lighting product. It is more surprising to know that choosing a product with lowest luminous efficacy wont help you to save electricity considerably like you think, since you need to install more light engines having lowest efficacy compared to a high efficacy product, which in turn will increase your initial investment and power cost. It is a best option to choose a product offering lower price/lumen and higher efficacy.

Key words: Lumen(Lm): Unit to measure light 

LED driver efficiency

 When calculating luminous efficacy we should consider luminous efficacy also, since the total power consumed by the LED driver considerable vary with the efficiency of LED driver. For example consider a LED driver is having a power output of 8W and with efficiency 90% , total power consumption of the product will be 8+10%=8.8W. Customer should consider this point while choosing a LED lighting product since the drivers are available with efficiency from 7 to 98%, choosing a driver with lower efficiency will lead to higher power charges compared to a driver with high efficiency.

• Saving money on a poor quality driver is a false economy since it will cost you more in the long run.

Power factor: A number for the future

Power factor generally denoted by PF, gives an idea about how effectively a driver utilises the electricity given to its input. PF has an effect on the country's electric grid. It is a number given between 0 and 1 and it is best to choose a HPF product always. Quality LED drivers are available with a power factor greater than 0.9.

CASE STUDY-HOSPITAL LIGHTING

Headline Savings
Annual energy savings: 236520 UNITS
Payback period: 1 YEAR
Annual CO2 savings: 10170360 kgs

Client
KIMS Healthcare Management Ltd,
Trivandrum ,Kerala

I was worried about the high power
consumption and failure rates of the CFL,
which lead to the wastage of manpower in
replacing them . It is quite inconvenient to
perform such maintenance in hospitals as they
are usually quite crowded . Switching to LEDs
was a solution to this problem . As the KIMS
management needed to evaluate the quality of
t h e l i g h t s p r o v i d e d b y S e m i l o n w e
requested for Samples of the lights. We were
able to note that Semilon's electrical and
lumen parameters strictly adhered to their
product data sheet . Usage of Semilon lights
helped our hospital win the EMC award 2012

for the most energy efficient hospital .

The Solution
We used our 18 Watt & 36 Watt LED 2X2
Square light using EDISON LEDS to replace
the conventional 36 Watt & 72 Watt lamps.
Drivers were specially made for hospital
application in order to avoid interference with
hospital equipment.

Kerala Institute of Medical Science one of
the Asia's leading tertiary care hospitals,
is a landmark heath care destination in
Kerala initiated by KIMS Health care
Management Ltd. The 600 bed multi
disciplinary super specialty hospital was
started with the objective of providing
world class health care services and
specialized medical facilities at affordable
costs. The clients objective was to reduce
the power consumption using LEDs maintenance
 free LED lights

CASE STUDY- RETAIL LIGHTING

Headline Savings
Annual energy savings: 9490 UNITS
Payback period: 1 YEAR
Annual CO2 savings: 408070 Kgs

Client

Variety Mall, Trivandrum ,Kerala.

When SEMILON approached me with their
LED lighting products , I was skeptical
about the new technology as I had not
seen LEDs being implemented for general
lighting purpose. I was doubtful about the
equivalence of Halogen lights and LED
lights. SEMILON demonstrated the
advantages of LED lights by
providing me with samples. The power
savings, the lights generated along with the
soothing ambience were quite evident.
They were extremely confident about the
performance of their products and provided
me with two years warranty. As the
commercial electricity tariff is higher in
Kerala these lights considerably reduced
the electricity consumption at my Mall.

The Brief

Variety Mall, located in the capital city of Trivandrum is a reputed exclusive fancy
store for women. The client required uniform lighting to showcase their products.
Reduction of energy usage.
Reduction of carbon emissions
Reduction of maintenance costs
Ambiance lighting.

The Solution

We used our 18 Watt LED down lights using EDISON LEDs to replace the 36
watt CFL lamps. Lumen method was adopted strictly and the glare index maintained.
These calculations ensured uniformity & provided an attractive soothing effect to
the products on display.