Interesting. I've not come across it happening, either, but I'm not totally surprised. The 'trigger' (S/L) input to a fan timer module typically goes through a high value resistor, usually in the range 150kΩ - 300kΩ, so the very most trigger current that could be required is only about 1mA. However, having gone through that resistor, the trigger input frequently goes straight to the input of a CMOS IC or FET, so the actual current needed to trigger may well, in some cases, be only a few μA - and it would not take incidental 'leakage' to achieve that.Interestingly, this is the first time I've come across a tangible problem caused by induced voltage. ... Like i say, I've never come across this before in a domestic situation and I wonder whether this fan's control circuitry is particularly sensitive to it. Still wouldn't stop me recommending it, as I haven't had an issue since.
+1 for the Soler & Palau TD160TFor in-line fans, go for the TD range http://www.tlc-direct.co.uk/Products/SLTDK160T.html for example
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