? regarding LED floodlamp with PIR

[ss]

Just a cheapo off ebay but has worked fine for last 2 years. A few nights back it stopped working, on investigation I noticed the PIR had some water in it, apart from the perspex window the only other place water could have entered was from the bottom panel that is screwed on, but that would defy gravity.

1. Is it possible that the water was a build up of condensation, the PIR is located above the flood.
2. I drained the PIR and left open for a couple of days to dry it out and is now working again.
3. Would the PIR benefit from a couple of `pin holes` drilled in the underside To aid drainage and prevent condensation.

[Harry Bloomfield]

ss a écrit :

I always drill drainage holes in anything supposedly water tight. They are often water tight as in holding water in.

[Johnny B Good]

Is exactly the right answer! Water vapour is a gas which can get past waterproofing and then condense inside when the temperature drops overnight. The waterproofing then acts as a barrier to the exit of this inexorable build up of condensate which eventually causes corrosion, often accelerated when it provides leakage paths within electrical circuits carrying DC voltages.

It's far better to provide free ventilation than to attempt a gas-tight enclosure (unless the unit is intended to be permanently submerged under water). The trick is to arrange that any such ventilation holes or slots don't provide easy access of moisture via precipitation of the horizontal kind. :-)

[Bill Wright]

Not pin holes. They won't help at all. 7mm holes. This happens a lot with CCTV housings. Put a ring of grease around the holes on the outside to stop creepy crawlies.

Bill

[Brian Gaff]

Silica Gell? In my experience its the cable entry where water gets in normally. Brian

[Alan Dawes]

I hope you were never an engineer in submarines! :-)

Alan

[newshound]

+1 (I tend to use 5 or 6 mm).

Grease won't stop everything getting in. I have wondered at times about putting a little roll of cotton fabric through the hole as a sort of wick plus evaporator (but I have never done it.

[Dave Plowman (News)]

;-)