Wiring up extraction unit - switches

[ProDave]

The manual for that unit is about as much use as a chocolate tea pot.

It has 3 speeds available.  You will probably only use 2 of them, the slow speed on all the time, and the faster speed when the bathrooms are i  use.

So the simplest way is probably use a relay to do the switching from slow speed to full speed.  Then you can activate the relay from any number of locations with for instance the timer unit that I used https://www.tlc-direct.co.uk/Products/SMTGBT4.html

 

[andy19812005]

my sentiments on the manual too..... so whhat your saying is that you have found a way to activate the fan from various rooms. did you have to run 3core+earth from each room to the multivent unit??? thanks

 

[andy19812005]

if i were to use a relay wouldnt the client have to make sure that the toilets CANT be used at the same time as the relay would be switching which could make an issue for the multivent?????

 

[ProDave]

The relay is to convert an on  / off from the switch(es) into a changeover contact to switch from low speed to high speed.

I used the timer switches I linked to earlier.  The output from those is switched L output from a relay inside the switch. They are not bothered by the output being turned on by the other switch.

I put the relay in a box next to the fan unit.  From there a 3 core and earth to each timer switch (neutral, live and switched L out from the switch unit)

 

[andy19812005]

cheers dave. thats proper food for thought..... i really appreciate your help, well eveyones that input for me. just so im clear.

im going to run 3core+earth from light switch to isolator switch, then another 3core+earth over to the relay, out from the relay and wire neutral into neutral. live into live and each switch live into L1,L2,L3 or L4. Does that sound right. Each bathroom and ensuite are small so which switched lives would you wire into if you were me????? Each bathroom/ensuite are literately 2m by 3m........ lol... i think my boss went over kill on these BUT he got all 5 for a brilliant price hence me having to find a solution to making it work...... thanks guys....

 

[Geoff1946]

I'm not sure if you should ever allow a feed to more than one of the L1, L2, L3, L4 terminals at the same time. This depends on the internal circuitry of the unit, but as shown on the schematic with the multi way switch only one could ever be live.  It may not matter at all. Perhaps a phone call to the maker's tech' help line would answer that.

 

[andy19812005]

thanks...... i defo will contact them on monday......

 

[ProDave]

I'm not sure if you should ever allow a feed to more than one of the L1, L2, L3, L4 terminals at the same time. This depends on the internal circuitry of the unit, but as shown on the schematic with the multi way switch only one could ever be live.  It may not matter at all. Perhaps a phone call to the maker's tech' help line would answer that.

My scheme with one relay forming a changeover from low to high speed, and then multiple sources triggering the relay complies with that. 

 

[andy19812005]

thanks for all your help.... relay it is..... il keel you all posted....