Total harmonic distortion

Hi everyone,

We have a large lamp replacement project where we change the existing light bulbs of a whole building to LED retrofits.

Currently our engineer is on a trip and I need to answer a question to our client's engineer and honestly, I have no idea as I don't really have anything to do with the technicalities of this project. They asked me about the THD (Total harmonic distortion) and whether we need to add a harmonic filter? Usually the THD for all our retrofits is below 20%...

Can somebody give me a "smart" answer? ;-)

I know, I might be totally ignorant by posting such a question, but I have no choice but to ask it. Thanks in advance...

Umm... without knowing anything at all about your project, and given its scale, I would recommend waiting until your engineer gets back or trying to contact him instead of possibly feeding your client wrong information.

Challenger said:

Hi everyone,

We have a large lamp replacement project where we change the existing light bulbs of a whole building to LED retrofits.

Currently our engineer is on a trip and I need to answer a question to our client's engineer and honestly, I have no idea as I don't really have anything to do with the technicalities of this project. They asked me about the THD (Total harmonic distortion) and whether we need to add a harmonic filter? Usually the THD for all our retrofits is below 20%...

Can somebody give me a "smart" answer? ;-)

I know, I might be totally ignorant by posting such a question, but I have no choice but to ask it. Thanks in advance...

Click to expand...

IEC (German standards) specify the maximum THD for LED products to be below 10% ie no more than the traditional fluorescent lamp. Logical because the power transformer in the building is already sized to take <10%. Once anyone introduces an LED system that exceeds the international standard, there is a risk of power cable heating, transformer heating and worst case, fire risk. There are few high quality LED design companies that have kept THD to below 10% eg CREE (US), Mitsubishi (Japan), and ELET (Singapore-HK brand). Go to www.elet.com.sg.