Sodium Floodlight Problems

benkay · Post by **benkay** » Sat Oct 17, 2020 10:05 pm

Hi all,

I’m looking for some advice on sodium (SONE bulb) issues I’m having with 2 floodlights on the same circuit.

We’ve just moved into a new house which has these on a timer. The timer was set completely wrong, so I changed that and can see (and hear) the sodium bulbs fire up.

However; they both turn on, start to warm up and begin to emit reasonably strong orange light.

Then around 20 seconds after turning on; they both suddenly go out, pretty much simultaneously (it’s hard to tell as I can’t see both at the same time).

I’ve tried swapping the bulbs for new and that hasn’t helped.

I know there’s an “ignitor” and a ballast within the fitting, and that probably one of these has failed but my questions are.

1. Presumably ignitor is fine as the bulbs do turn on initially?
2. If ballast; could it be a failure in one of the floodlights is causing the other to turn off too? Or is it just unlucky and both ballasts have failed?

Thanks. Ben

Someone-Else · Post by **Someone-Else** » Sat Oct 17, 2020 10:11 pm

The sad truth is it will cost more in replacement part(s) than it would to buy a new LED flood light.

benkay · Post by **benkay** » Sat Oct 17, 2020 10:19 pm

Really? I can get the ballasts for £25 each (same part as what’s in now).

Decent quality LED floodlights to match output of 70W sodium seem to be £75+

Someone-Else · Post by **Someone-Else** » Sat Oct 17, 2020 10:36 pm

I wouldn't want a 70w LED lamp, way too bright, sodium lamps being orange/yellow you do need a brighter light to see by, but if it's a white light it need not be so bright.

big-all · Post by **big-all** » Sat Oct 17, 2020 11:39 pm

70w led is around 5x100w incandescent[normal ] bulbs so floodlight in a fooball stadium type light

a 70w sodium is about 6500 lumins
70w led is similar but suspect ballast and loading makes sodium much less efficient so probably more input watts and only output value quoted :dunno:

ericmark · Post by **ericmark** » Sun Oct 18, 2020 6:32 am

The sodium orange light made stone churches look good, and the theory was our eyes can see orange light better than white so a 70 watt sodium would need a 80 watt metal halide to have same ability to see with, but I swapped the running gear to metal halide as wanted whitish light, the sodium light did not reflect well with hi-vis clothing so it was a safety thing, going to white light, same with street lighting, white with show up with hi-vis clothing, so move to using LED, however very little gain running cost wise.

The limit without planning permission is 150 watt, this was for a tungsten bulb, as yet don't think converted to lumen in law, but it would be around 2500 lumen, so one should really consider 2500 lumen as being the max. So around 35 watt Sodium or 25 watt LED. Of course to be challenged some one needs to complain, the council do not walk around checking, but it makes sense to keep within planning permission limits.

One reason for sodium is not mistaken for a head light, so cars do not dip head lights for a sodium lamp on a house, but may for a white light, the 70 watt was the standard energy saving replacement for the 500 watt quartz lamps, so it was a popular size. But for you I would guess wrong bulb, you can get 70 watt sodium bulbs with both external starting gear and internal starting gear, the added problem is a lot of sodium bulbs are now obsolete, so often the control gear has to be changed, likely better to convert to LED, however I will continue to use my 70W metal halide until the bulb goes, did have a spare, but wife fitted it to an ikea standard lamp, E27 so fitted, but fuse went bang and no longer have a spare bulb, should have kept garage locked.

Rorschach · Post by **Rorschach** » Sun Oct 18, 2020 6:36 am

big-all wrote: ↑Sat Oct 17, 2020 11:39 pm 70w led is around 5x100w incandescent[normal ] bulbs so floodlight in a fooball stadium type light
a 70w sodium is about 6500 lumins
70w led is similar but suspect ballast and loading makes sodium much less efficient so probably more input watts and only output value quoted

It's a common misonception that sodium lights are less efficient than LED, they are surprisingly similar. The main reason for them being changed over is not running cost or even unit cost (an LED is much more expensive), it's time. LED's last much longer than sodium lamps so need to be replaced far less often.

Nos · Post by **Nos** » Sun Oct 18, 2020 7:22 am

You only need a 30W LED it will illuminate a tennis court, a 50W will light up a football pitch

well nearly, the cost is about £30/40 each.

kellys_eye · Post by **kellys_eye** » Sun Oct 18, 2020 9:34 am

Not sure about the wattage figures quoted to light up a tennis/football court! There will be a minimum lumen requirement (as per commercial premises) to do sports safely and no way would 50W of LED cover it else football stadia would have tiny masts/lights. I recall refitting mobile generator/site lighting sets from sodium to LED and the new LED units were FOUR each at 100W - and that's just to illuminate worksites.

Nos · Post by **Nos** » Sun Oct 18, 2020 10:46 am

kellys_eye wrote: ↑Sun Oct 18, 2020 9:34 am Not sure about the wattage figures quoted to light up a tennis/football court! There will be a minimum lumen requirement (as per commercial premises) to do sports safely and no way would 50W of LED cover it else football stadia would have tiny masts/lights. I recall refitting mobile generator/site lighting sets from sodium to LED and the new LED units were FOUR each at 100W - and that's just to illuminate worksites.

It was meant tongue in cheek.