LED Light & Driver Failure

LED Light

LED Lamp generates triplen harmonic. It triples on neutral & pervades in the power system. Droops light efficiency & brightness & fails LED Light & Driver. If there are a significant number of LED light drivers and SMPS based electronic gadgets in a building's electrical supply, as in the case of shopping mall, hotel, hospital, corporate-building, manufacturing shop floor etc., it will cause a high neutral current problem. Infirmness in the neutral wire with high neutral current is an electrical fire risk.

As per Ballpark estimate, LED Drivers fail 90% and LED Lights 10% of all incidents. Why do LED Light and Driver fail prematurely and much before their guaranteed life by its OEM?  Accelerated ageing is the root cause which is primarily produced by the following reasons. 

High Temperature primarily from LED's triplen harmonic current

Voltage Sag and swell from the harmonic-rich power circuit   

Overload due to harmonic and voltage fluctuation  

Triplen harmonic filter provides a sustainable solution to all the three primary reasons those cause failure in LED light and driver.  It connects at the nearest 3phase LDB of a lighting power distribution circuit from where individual R-Y-B phases branch out and connect to all the LED lamps. The triplen filter provides a low impedance zero sequence current path and traps all the triplen harmonic currents from LED drivers which otherwise would get absorbed within the LED lights and drivers causing it to heat up incrementally.  The triplen filter electromagnetically locks the R-Y-B phases into a single magnetic circuit which prevents momentary voltage fluctuation. It is the most efficient surge suppresser and much effective than the ordinary RC-based Surge Protection Devices, SPD. Triplen filter protects equipment from voltage fluctuation and power surge which may occur either frequently as in case of LED light or momentarily as in case of elevator malfunction in the triplen harmonic rich environment.    

Why LED Light discolor to Yellow and Flicker before failing

Yellowing in the LED bulb and strip is an indication of its impending failure from heat due to ageing. The possible cause is overheating due to overload.  In addition, the diffuser which is used to disperse light from LED and reduce glare and the sealed-in epoxy resin which is used to encase the LED-chip, age faster with the heat from over voltage and the Blue-UV-LED light. Which discolours and degrades the LED light into a yellowish form. Triplen harmonics cause over voltage spikes and heat in the LED driver.

LED light comes from a combination of three LEDs and resistors in one package - Red Green and Blue, RGB. The higher the frequency in light requires a higher energy photon which is supplied by a higher forward voltage. Red LED requires lower energy photon than the Green and Blue LEDs. Over voltage spikes from triplen harmonic and the resulting heat in the LED driver cause the green and blue LEDs to lose extra brightness than the Red LED since they work at a higher dc voltage level. Which further discolours the LED.  Eventually, the LED Driver fails to convert current properly and maintains a uniform voltage which means that the LED driver will no-longer react to overload. The LED light starts flickering or flashing which is evidence of its inevitable failure.  

LED Driver Configuration

Light Emitting Diode (LED) lamps are becoming increasingly popular in replacing incandescent lamps and fluorescent lamps owing to its energy efficiency, resilience and long life and being environmental friendly. It does not contain hazardous toxic substance like mercury. Individual LED light is illuminated by 2/ 4V DC supply. With a LED light fixture, a set of series parallel LED lights receive power supply either from a constant current LED driver 350/ 750mA DC or constant voltage LED driver 12/ 24V DC. LED drivers are power supply devices that convert 120/ 240/ 277V, 50/ 60Hz AC supply to DC power as required by the LED lamps. It manages the amount of power for a LED lamp or LED lighting system and protects individual LED lamp from thermal runout and power surge. Since LED drivers are a switching device, it generates harmonic currents, and causes electromagnetic interference (EMI) problem for the building's electrical power system. It creates a significant percentage triplen harmonic current also known as zero sequence harmonic current into the facility's electrical power system which unlike phase current does not get cancelled but trebled at neutral.

Giving an example, if a 3phase LED DB has 10A each in R, Y, and B phases with 30% THDi total current harmonic distortion; each phase would carry 3A triplen harmonic current. That being in phase with the neutral conductor would add up to 3A+3A+3A = 9A in the neutral conductor consisting mostly of 3rd harmonic (3 x 50/ 60Hz) currents and 9th harmonic (3x 50/ 60Hz) currents. These high frequency neutral triplen harmonic currents are all pervasive and with any infirmness in the building's neutral/ ground system, it's a serious electrical fire risk that could strike as a bolt from the blue.

What further complicates the facility's electrical fire risk is, its extensive cabling network. Every modern building employs a labyrinth of cable networks that passthrough floors, risers/ shafts, and ducts/ trenches. If Triplen Harmonic Currents are not contained at each floor level they would travel through the cable labyrinth and multiply freely. Unlike the phase current conductors, neutral/ ground paths must be secured firmly, always, and infirmness is a very serious electrical fire risk. Besides the buildings' extensive cable networks are not suited for the onslaught from the high frequency triplen harmonic currents on a 24/7 basis. It eventually loosens up somewhere. Encon triplen harmonic filter removes those dangerous high frequency triplen harmonic currents also called zero sequence harmonic currents from the building's electrical power system, through a floor by floor, and section by section implementation procedure. And provides a comprehensive electrical fire safety solution for the entire building.

How to Solve LED Light and Driver Failure

Triplen harmonic current easily penetrates the LEDs power supply driver. If significant number of LED lamps are installed as like in a hospital, hotel, corporate building, shopping mall, airport etc., the resulting triplen harmonic currents would circulate in the building's electrical power system and get absorbed into LED drivers' power supply system heating it up. That heat build-up would eventually take its toll. Encon triplen harmonic filters, apart from providing comprehensive electrical fire safety solutions, also eliminating failure of LED power supply drivers and LED lamps.

That apart, Encon harmonic mitigation solutions improve power quality by reconstructing harmonically distorted waveform back into sine wave, balance 3phase voltage and currents and is an effective surge suppressor. It effects energy conservation and extends LED light life and its performance, and protects sensitive equipment within the building applications.