Having bought a Primair controller only to find it makes my fans buzz like hell, i did a bit of reading on here and i have decided to build a variac fan controller a la Rastajedi style.

So ive got 2 clairtronic 2 amp variacs and i would like to use one for my inlet fan and one for the extract fan. Im using 2 x honeywell 6360 thermostats and what i would like to do is have the fans running on the set speed on the variacs and once the temperature is exceeded on the thermostat have the fans kick in on full.

Ive basically got a seperate controller setup for each fan ,but housed in one box. I could do with some help wiring it all together, im usually O.K at wiring but seem to be having a mind blockage.

Which terminals do i need to connect what to on the variacs? and which terminals do i need to use on the thermostat there are 4 + earth.

Any Help much appreciated.
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can you get me up the wiring diagram of the thermostats, and the top of the variac terminals ta

also by the way, if you set the exhaust to come on full speed at a lower temperature than the intake, then you'll have a three speed temperature controlled setup lo lo, hi lo and hi hi

Hi Scraglor Thanks for coming along to the rescue. It was you and whazzup and R.J that inspired me to make this so thanks

O.k its a bit tricky to get a clear shot of the variacs now they are in the box so ive took a shot of the wiring diagram, hope that helps.
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Heres a shot of the thermostat

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And the wiring diagram that came with it

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Didnt know id have 3 speed but yeah makes sense, wooohooo

ok, you got the right thermostats which is good, are they the ones Rj used?

anywho, your 240v from the mains connects between terminals a and c, doesn't matter which way round really, just means one way you'll have to turn the knob anti clockwise to turn the fan up and the other way you'll have to turn the knob clockwise to turn it up.

make sure which ever side you end up connecting neutral to, is the same side you connect your fan neutral to. (again you could connect your fan "neutral" to either live from mains or neutral from mains. it's just a reference voltage to your variable output, but for simplicity's sake, neutral from fan to neutral from variac)


your variable output E connects to terminal 3 of your thermostat.

mains live connects to terminal 4 of your thermostat

L1 feed to your fan is from terminal 1 of your thermostat

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Many Thanks Scraglor, Finally got it finished just now and works a treat, well i think it does. It makes the lights on the 4 way leads im using as outs dim so i presume itll work on the fans, ill find out in a minute.

The stats i used were Honeywell 6360 's I think Rasta Jedi used Sunvics ???

Thanks again man your a star.

looking good DeeCee

im also planning on making the same controller,
is there any chance of some pics of the inside & the wiring ?

im a bit lost with how you wired up the thermostat, is this how you did it ?

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thanks

almost, ignore terminal 2 and the load symbol.

fan live goes to terminal 1

mains in goes to 4

variac variable output goes to terminal 3

neutrals from fan and main connect together, i'm guessing this ha been done inside the main unit though, as only 3 cores are needed to go to the thermostat

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Its a bit tricky to get the top of the box to get a good clear shot of how i wired it.

Basically youll need some 4 core 1.5mm flex for the stats, i used 2.5mm for the mains in and 4 way extension leads for the power outlets. Also some connector strips and cable ties etc.

Ive drawn a diagram of how i think i wired it

The only thing is the fan controller seems to be working anti clockwise to speed the fan up.

I presume this is o.k and i dont mind to be honest so havnt sussed out how to change it, but i imagine the variac contacts are the wrong way round??
Scraglor, Is this safe??

perfectly safe buddy, is it only on one if them? all you have to do is switch the live in and neutrals around