Spooky PIR!

[gman76]

Can anyone offer an explination as to why about 5 times out of 10, my outside security light comes on when my bathroom light is switched off? The security light is a bulkhead design with integral PIR underneath mounted to the outside of the bathroom wall with a GLS lamp fitted. The bathroom fitting is a sealed unit with a 2D style energy saver. Both lights are on the same MCB in the CU.
This never happens when the bathroom light is switched on - only off.
It doesn't really worry me - I'm just intrigued as to why this happens!

Any help appreciated!

 

[breezer]

spike

 

[gman76]

Thanks Breezer - forgot to mention the rest of the fittings on the same circuit have energy savers fitted (although BC types). Why is it only the 2D lamp that causes this?

 

[Taylortwocities]

Spike, or it could just be spite

 

[miajanjua]

spike

Connect a 1.0 Microfarad 250V AC Capacitor across the L & N at the 2D terminals.

 

[Taylortwocities]

I beleive that your cap. should be 400V working if you are going to do that....its the peak voltage you have to cater for when bunging a cap. on an ac supply.

TTC

 

[ricicle]

You are right TTC

 

[Taylortwocities]

I'm right yippee!!

Capacitors working voltages are the DC value. AC values are RMS (ie .707 of the peak) So for 230 volts AC (RMS) the peak will be around 325volts.

TTC

 

[THRIPSTER]

And should be X reated

 

[gman76]

Thanks for all your responses, I figured a suppression cap might be the answer if the cause was a spike on the mains.

This kinda begs the question as to why the manufacturer of the 2D light fitting didn't include it as standard? Or would it be down to the lamp itself? Sorry, but I don't have a great deal of experience with this type of fitting/lamp.

Thanks again.

 

[Steve]

It also begs the question of why the PIR is so sensitive to mains spikes.

 

[gman76]

Very true, as I also didn't mention that there are two further PIRs on the same circuit with no problems! I wasn't sure if the reason could possibly be due to RFI, as the fitting in question is the closest to the bathroom fitting? These lamps emit all sorts of things?

 

[miajanjua]

spike

Connect a 1.0 Microfarad 250V AC Capacitor across the L & N at the 2D terminals.

I thought it was understood that it means a working voltage of 250V AC, its not a DC working voltage of 400V.

It has to be non-polarised capacitor for working at the mains voltage.

 

[gman76]

Your original reply was duly noted! Further more, if the problem persists beyond my patients - I will take your advice.

Thanks All.

 

[breezer]

This kinda begs the question as to why the manufacturer of the 2D light fitting didn't include it as standard?

cost


say you are producing 1000 lights / week, cap costs say 10p, thats £10 you would save/ week = £520 / year