Motion sensor garden lights coming on when kitchen oven switched on

StiffOldMan

Hi guys, I had an electrician put two LED motion sensor flood lights on the back and side of my house early last week. I noticed after the install that they were on a lot over the last week. I put it down to cats or wildlife and that the lights sensor was too sensitive and timer set to a long time. So over the weekend I got the opportunity to turn down the sensitivity to pretty much zero, but the lights were still coming on by themselves. I noticed that when the oven was switching itself on throughout a cooking cycle the lights would come on at the same time, at the back and side of the house. This happened I'd say 20 times through a 2 hour oven cook. I noticed that they came on intermittently aswell with the light switch in the kitchen. Sufficed to say, the motion sensor reacts to internal power to other devices being switched on???

Im going to ring my electrician and see what he says but wanted to run it by here to see if its a common thing? The house is not old, about 15 years. The back lights are almost always on when normal everyday electrical devices are used in the house

Stoner

Any chance you have an extractor hood venting near to the light fittings PIR

whizbang

Its electrical noise, not thermal.

do you have florescent strip lights in the kitchen ?

StiffOldMan

Electric noise! There are no florescent strip lights in the kitchen. Its as if the cooker/light switch is causing a surge/voltage spike which enters both sensors causing them to react and switch on. Is there something I can do to the motion sensor to protect it against any type of surges?

Stoner

StiffOldMan wrote:

Electric noise! There are no florescent strip lights in the kitchen. Its as if the cooker/light switch is causing a surge/voltage spike which enters both sensors causing them to react and switch on. Is there something I can do to the motion sensor to protect it against any type of surges?

I'm not sure it's electrical noise.

If the cooker is on for two hours with a resistive load on its own dedicated cct it doesn't sound that noisy to me.

And noise from fluorescent fittings is usually at its worst while switching and to impact on the outside lights it would mostly be on the same lighting cct. But if they have been in for two hours ?

If it was thermal it wouldn't impact on both fittings so it's not that unless they are wired to operate as one, linked and the main one is near a heat vent or the gas vent. This can happen, I've seen it before.

Those lights are programmed to turn on for the duration of the timer when you flick the switch. So a poor connection on the looped feed would set them both off.

I'm struggling to see how it's your cooker tbh

2011

I have a different theory.

Do you notice that any of the lights in the house dim momentarily when the cooker is switched on?

When the cooker switches on it draws a large current, this can cause the supply voltage to the sensor to dip. This can reset the sensor causing it to shutdown and then switch the lights on just like it does when it is powered up initially.

"Budget" sensors are known to behave erratically, you get what you pay for.

For reliable switching, spend a few bob extra and use high quality PIRs such as a Stinel.

StiffOldMan

2011 wrote: »

I have a different theory.

Do you notice that any of the lights in the house dim momentarily when the cooker is switched on?

When the cooker switches on it draws a large current, this can cause the supply voltage to the sensor to dip. This can reset the sensor causing it to shutdown and then switch the lights on just like it does when it is powered up initially.

"Budget" sensors are known to behave erratically, you get what you pay for.

For reliable switching, spend a few bob extra and use high quality PIRs such as a Stinel.

I think you may have hit the nail on the head. Yes the lights do slightly dim for a split second as far as I recall. I'll check again (ask the wife to cook something decent )

The cooker is on its own on circuit I believe as it has its own dedicated trip switch, so the lights are on a different circuit if I understand correctly but yet they react to the cooker coming on during its cooking cycle. The two lights are not wired as one but yet have both responded to the cooker coming on at the exact same time. They act very much like they reset..

I came in from work last night, opened the front door, switched on the front outdoor light and could see through the house that the back light reacted and came on aswell!!!!

Ive asked my electrician to come back to have a look as these sensors are reacting too much. Here's the exact one https://www.amazon.co.uk/LED-Robus-Activate-Floodlight-Graphite/dp/B01LDGEA2S/ref=sr_1_3?ie=UTF8&qid=1478106811&sr=8-3&keywords=robus+30w+led+floodlight

2011

Although Robus make some good stuff my experience with their PIRs has been disappointing.

It is normal for a cooker to be on a dedicated circuit, this will not prevent the PIRs experiencing under voltage.

I think the fact that the lights in your house dim when the cooker switches on speaks volumes. This may be an symptomatic of other issues.

colm_mcm

Don't some of these PIRs have a function where you can manually turn them on by flicking the switch on>off>on?

Could be mistaking the drop in power for this?