Changing “fan boost” switch

[seanuk]

Our new build have “fan boost” switches for the extractor fans which look to me like a standard light switch. It has connections on the back going to COM and L1.

I wanted to swap it for this switch with an LED indicator light on it, but it has different connections (L + N, out and L + N in)

Is it okay to use this switch for it? If so which connection points do I use for the old COM and L1?

Thanks

 

[stem]

You only have 'live' wires at the switch. The brown wire will be the live supply and the blue wire with the brown sleeve the switched live. However for the LED to work you will probably need a neutral, which you don't have. But you could try and see.

COM = L in
L1 = L out

 

[Jurassicspark]

Our new build have “fan boost” switches for the extractor fans which look to me like a standard light switch. It has connections on the back going to COM and L1.

I wanted to swap it for this switch with an LED indicator light on it, but it has different connections (L + N, out and L + N in)

You don't have a neutral at the switch.

Unfortunately, the LED won't turn on as it requires a neutral.

The switch will be able to turn the fan on off though. (I'm sure the original switch already achieves that function.)

Is it okay to use this switch for it? If so which connection points do I use for the old COM and L1?

There is no point, if you are only seeking for the LED light to illuminate from switching the old switch to the new one.

Sorry to be the bearer of bad news.

 

[seanuk]

Thanks for the replies guys.

Guess I’ll just replace it with a normal silver switch with the same connections.

 

[sparkwright]

Don't forget the earth connection to the new metal switch.
And any other new light switches you fit.

 

[Harry Bloomfield]

I wanted to swap it for this switch with an LED indicator light on it, but it has different connections (L + N, out and L + N in)

Connect the brown to L IN, blue to L out, as said above, you must connect the switches earth terminal, to the earth wire.

 

[foxhole]

https://amzn.eu/d/9a8Kxyi

 

[Harry Bloomfield]

https://amzn.eu/d/9a8Kxyi

That, might not work reliably, in this application. It's designed to expect the 240v across it, while ever the light is off, to charge it up.

 

[foxhole]

That, might not work reliably, in this application. It's designed to expect the 240v across it, while ever the light is off, to charge it up.

?

 

[SUNRAY]

That, might not work reliably, in this application. It's designed to expect the 240v across it, while ever the light is off, to charge it up.

?

That switch will require power to operate, it will contain some form of storage device (usually a capacitor) for the purpose and will require a 'charging current' derived from the load while switched off (typically a lightbulb).

Depending on the fan used the boost function may not present a load as such, rather like a timer fan where the trigger input is very high impedance (typically a 1MΩ resistor).

The usual result will be the confusing way the device is either permanently 'triggered' due to the required charging current or due to the low charge current; the capacitor is permanently discharged due to electronics in standby. A third possibility may be it will start the fan but only run for a short period due to the very low charge.

Of course the 4th option is it could work.

 

[Harry Bloomfield]

The usual result will be the confusing way the device is either permanently 'triggered' due to the required charging current or due to the low charge current; the capacitor is permanently discharged due to electronics in standby. A third possibility may be it will start the fan but only run for a short period due to the very low charge.

Thanks, that is what I had in mind. It would be a shame for the OP, to waste money buying one, only to find it wasn't compatible with his use.