CFL's & PIR's

Apr 12, 2010 4 Replies
T

I've only just noticed in the Toolstation catalogue that some of their CFL's seem to carry the warning 'not suitable for dimmers, PIR's or electronic switching'.



I'm aware that dimmers & CFL's don't get on.



Not seen this warning in the TLC book.



Recently had a case where a lady wanted a PIR light

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for like replacement, but she didn't have a 60 ES incandesanct lamp.



12w CFL fitted & didn't work properly. 60W incandescent & still no good.

I'm assuming the CFL has damaged the electronics in the PIR somehow?



No mention of CFL's in the instructions whatsoever, so its going back.



I'm assuming that CFL's aren't compatible with PIR's, but I'd just like to know why?


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O

  1. Some PIRs etc (usually the ones that replace a switch) don't have a neutral and rely on a small current flowing through the filament of a conventional lamp to power their electronics.
  2. CFLs are an inductive load and they are more difficult to switch than an ordinary resistive load.

Some PIRs are compatible with fluoro lamps - usually the ones that have a proper relay and click when operating.

Owain

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J

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- I can't believe that you are asking this after using this group for so long - and professing to be a professional. It has been covered in some way loads of times over the last few years that I have been reading the articles.

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J

Possible, but equally likely it was duff in the first place (some of the PIR controlled lights are pretty poor - I have certainly have had some DOA)

They are usually ok on most PIRs. The PIRs likely to cause problems are the ones designed to fit as a replacement light switch, and hence operate without a dedicated neutral connection. These will tend not to work as intended, and may also cause the lamp to flash periodically.

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