LED lighting and Networks

Posted by: james n on 16 June 2014

Just an observation which may help others having strange Wi-Fi and wired network problems, especially as LED lighting is becoming more prevalent .

 

We'd taken advantage of the in-room Wi-Fi in the hotel on a recent holiday. I noticed it would go from being very fast to extremely slow - especially after dark and initially thought it was due to increased usage over a limited bandwidth connection. After a day or two of this behaviour, i'd happened to switch off one of the lighting bars above a mirror in the room and found the Wi-Fi improved. Switching back on killed it again - the signal strength dropped quite considerably too. After taking off the diffuser panel on the light, i found four LED lighting modules inside - all except one were marked with a CE label. With the non CE module removed Wi-Fi was fine but as soon as i put the non CE marked one back in, it killed the Wi-Fi. It looked the same, worked just as well from the light output but must have been radiating quite a lot of crap out via the mains wiring over quite a wide bandwidth. It seems that some LED bulbs, especially very cheap copies leave out the suppression network for the switching LED driver so you end up with a nice little transmitter, its effectiveness in this role depending on mains wiring length and routing. CE marking is also not a guarantee that it's OK, given the number of cheap alternatives coming from the Far East.   

 

So if you are having strange problems with Wi-Fi or Homeplugs (let's not go there on crap on the mains), it might be worth checking your LED lights aren't the issue.

 

James

Posted on: 16 June 2014 by Jan-Erik Nordoen

Well spotted and well researched James. Thanks for the tip.

 

Jan

Posted on: 16 June 2014 by Huge
Originally Posted by Jan-Erik Nordoen:

Well spotted and well researched James. Thanks for the tip.

 

Jan

+1, Excellent info, thanks.

Posted on: 16 June 2014 by Simon-in-Suffolk

James, interesting to see they are radiating at least upto  2.4GHz.. that is some faulty device!!

A close family friend of mine is an electrician and fits many LED devices and he does seemingly have issues with RF noise radiating from the devices and connected wiring  affecting domestic radio even on CE marked devices, but he has never mentioned impacting wifi.. I will relay your story to him...

 

Simon

Posted on: 16 June 2014 by DavidDever

If it's a certified Zigbee Light Link device AND you're using a fixed Wi-Fi channel at channels 3/4 or 8/9, yes, this can definitely happen, as the profile is designed to coexist between the most common (in this case, channels 1/6/11) frequencies in the 2.4GHz spectrum, i.e., right around your Wi-Fi channels.

Posted on: 16 June 2014 by Mike-B

I've got 7 x 5w (50w eq) LED in my living/listening room, 8 of the same in the hall & stairs - all on dimmers & 6 x 7w in the bathroom.

I took some professional advice & did some research & experimentation before buying. What I found above all was cheap is not a good idea, you are best advised to stick with well regarded brands & most are not cheap & if you want dimmers, only some lamps will dim properly & be sure to use only dimmer switches that are approved for the brand.  But to repeat, good LED ain't cheap.

None off my lighting interferes with wifi or hifi - range or SQ are not affected.

Posted on: 16 June 2014 by james n

I've come across LED lights interfering with weak DAB signals but nothing this bad but i was quite surprised it was knocking out the Wi-Fi. I'd have liked to investigate a bit further but i was on holiday and should have really been switching the brain off