Failure Reduce in LED Bulb

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I need help regarding MOV and Fuse failure in LED Bulb of 9W.
Due to Bad Power Supply Condition in some of the areas in India facing Bulb failure.
Most of the failure found in lamps are MOV burnt and Fuse Burn.
MOV value is 07D511K type Vrms 320V.
Surge Rating is 2.5KV.
But having this capacity still get failure issues.
So what can be done for to reduce failure.

Please help regarding this.......

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At what condition is the failure of MOV and fuse occurs? Is it during surge test? or during operation in actual application?
If it's during surge test, then I would suggest use a MOV with higher surge current rating (e.g., 2.5kA).
If it's during operation in actual application, which you said has a bad power source condition, then maybe check the actual swing of the input voltage in that area. Perhaps, the actual input swing exceeds the AC voltage rating of the MOV causing it to conduct at normal operation. If this is the case, then you may choose a MOV with higher AC rating (e.g., 350VAC). Then, check the response on surge test.


Sounds like the MOV is doing its job and protecting the rest of the ckt from excessive over volt surges...

Hi ,
Thanks for the feedback.
Bulb Fails in actual application, I will check the voltage swing and update and also as per the feedback I will try with MOV Rating 350VAC.

Once again thanks for the feedback.

You said only the MOV and the fuse blew, you omitted to say the bulb failed as well.

If the components in the power supply to the bulb are not high enough rated in voltage - then you cannot protect them with a simple MOV, a 350V MOV starts to draw high current at around 650V, a 320V MOV at around 600V, it is easy for a fast spike to get in and kill your circuit, esp if you have a too low diode doing rectification on a flyback...

The Power Quality that you have described comes from the LED drivers itself. The failures generally do not happen if numbers of LED lights are less. However, with larger numbers like in Malls, Hotels, Large Offices and in manufacturing shop floors the Triplen Harmonics from the LEDs are large enough. The harmonic's waveform spikes also are seen as voltage spikes and many OEM have termed them as voltage fluctuations. I attended many Elevator Malfunctions and its VFD drive failures for large corporate buildings after they converted to LED lights.

If your failures are repetitive and happening when you have installed a large number of LED lights like in corporate buildings etc.- it's most likely the Power Quality from the LED lighting circuit itself. Read the web-page for details. ---->