Why do street lights flicker in snowy weather?

In the UK we currently have cold winds and snow.
A radio phone-in got a lot of people talking about flickering street
lights.
Is there a real connection between bad weather and flickering street lights. If so then how does it work?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/18/09 6:21 PM, Eddie wrote:

Can you be precise? Frequency of flickering? Snow required? humidity? Cold? Exceptions?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sam Wormley wrote:

Tea.
--
Adrian C

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 00:27 19 Dec 2009, Sam Wormley wrote:

The flicker I saw a few days ago was about 2 or 3 times a second.
The radio callers weren't specific about their local conditions but just said "my street light is flickering here too".
In my case in South East England a cold snap was just starting and there was about 2 inches of snow and temperatures were a few degrees below freezing. The winds were unusally high for the area (perhaps VERY roughly 30 mph).
It could just be coincidence but the radio callers got me thinking that maybe there's an electrical explanation. Any observations or ideas?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Eddie wrote:

I wouldn't have thought there was anything electrical about it, unless it was variation in the supply. Most street lights are low pressure sodium lights and run internally at about 100C in order to vapourise the sodium - all internally generated by the initial argon/neon discharge - one reason they take several minutes to warm up as do most light sources other than incandescent or LED light sources being notable exceptions.
This in itself makes them insensitive to ambient conditions.
There would be a variation in warm up time depending on the ambient temperature - the colder it is the longer it takes. (You can see this with CFL lights especially ones used outside. The ones I have in my yard take several minutes to produce full output especially when its really cold outside). Even the HP sodium lights you often see take time to warm up as well. They are like LP sodium lights except the two well known sodium lines are pressure broadened to give better colour rendering.
--

I'm not apathetic... I just don't give a sh** anymore

?John Wright
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, it's quite simple. Callers to local radio stations are drawn from the lower 5% of human ability. Anything they say can be safely ignored because it's bound to be vacuous crap. HTH.
What local radio needs is another James Stannage to tell the dimwits phoning in that they are indeed dimwits who are a waste of oxygen that could be used more productively on keeping slugs alive.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Sadly, I don't think there will never be another James Stannage. Thanks for reminding me of him. You and he have a lot in common. :-)
--
Mike Barnes

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Such kind words, and I do actually mean that. I had a deal of respect for the bloke ever since I accidentaly tunesd into Piccadilly Radio when I was a student. Listening to him baiting the drunks who phoned in late on Friday night was a pleasure.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 19 Dec 2009 11:24:32 +0000, Steve Firth wrote:

Heh. I remember him. Alan Beswick was another local radio hero...
Mike P
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

He was awesome. I remember listening to his late night show on Red Rose Radio in the mid 90s. He had a particular ability at handling pissed up scousers who called in to heckle him.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Steve Firth wrote:
<snip> that wasn't helpful at all.
/BAH
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/19/09 3:37 AM, Eddie wrote:

So it could be a street light on its "last legs" and the "feedback" internal to the gasses and current may have some temperature sensitivity. If that is the case, the "flickering" will only get worse.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Probably a disturbance in the power distribution grid. Somewhere on the grid a transformer probably blew out, or a power line failed.
I saw a transformer fail last week and it was very, very bright. Lots of arcing and it lasted quite a while. I think that it was arcing for about 5 or 10 minutes, looked like a welding light. That can cause fluctuations in the power distribution grid which will cause lights to flicker - for sure.
The same thing happens when they electrocute an innocent person in Texas - all of the lights flicker and the face of Jesus emerges from the white noise on their TV sets.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/19/09 9:56 AM, Huang wrote:

I had no idea!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
[snip]

Well, if they are all guilty, you wouldn't see it very often
Jeremy Parker
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I've seen this with SOX (low pressure sodium) lamps as one of the end-of-life failure modes, although it's not the most common SOX failure mode. With the 35W SOX used on smaller roads, it could be the starter repeatedly restarting a lamp which isn't sustaining an arc anymore.

Description too devoid of information to even guess on the cause. They could each be describing something completely different.

If the streetlamps have their own didicated overhead supply (now very rare in the UK), then maybe that's arcing somewhere in the wind.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Eddie wrote: ...

At the start of the cold period, my house lights and those of a friend, both also in SE England, flickered a few times. I assumed the weather was affecting overhead power lines somewhere, which resulted in automatic switches having to transfer load.
Colin Bignell
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 24 Dec 2009 07:38:28 +0000, "Nightjar <\"cpb\"@" <"insertmysurnamehere> wrote:>

Doesn't that sort of thing happen when intermittent shorting or arcing trips a breaker somewhere and the breaker makes automatic re-tries ?
Derek.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 27 Dec 2009 21:40:56 +0000, Derek Geldard

I would describe such events as a bit more than a flickering.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
lurch wrote:

That would be the start of the sequence and, if the fault was transient, it would result in the line being reconnected. However, if, say, a line had been brought down, then the load would be shifted to minimise, as far as possible, the area affected.

They needn't be, unless you haappen to be within an area that ends up disconnected as a result of the power switching. However, I do recall one incident around 35 years ago, when a fault at a time of high demand resulted in cascading overloads that blacked out much of SE England.
Colin Bignell
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.