A quick sketch/diagram of how a standard room thermostat to override a fan speed controller works.

[attachmentid=70495]

Hi,

Just thought i'd carry it over to forums (was in pm) incase this will help other people or any leccys will know any ways of doing this.

What I would like to do is have my Fans Idleing via a B&Q Fan Speed Controller so theres some air movement. When the temp gets too high, I would like my Habistat Cool Control Thermostat to kick in and give the fans full power.

However, the way the Habistat is wired it doesn't seem atatll easy to do without some possible modifications or some other way.

The habistat is just an in/out setup. What ot1 pictured is for a Honeywell, although this has helped me a lot I still can't get mine going unfortunately due to the Habistat wiring as the neutral gets turned off as well as the live when the Habistat turns off. Thus there is no neutral for the fan speed controller/fan.

If anyone has any ideas, I would be most grateful,

I have just included a quick drawing of the in/out habistat. I do not know if it is possible what I want to do without some other components.

Many thanks

Try it this way.

cheers ot1, thinking of doing this soon,
Any chance we could get this pinned?

That is so easy to understand, I think I would be confident to try it.

This could probably do with pinning at the top of the subforum. So many people ask about this.

EO.

Hmm...what I need to be able to do...and I'm sure loads of other peeps too, is to have fans idling at lights off, then kick into a higher idle speed when thermostat kicks on. At no point should my fans run at max (noise and outlet constriction reasons). Any idea's on that? (2 output relay/2 dimmers and a thermostat?)

This is live only connections for preset low night fan speed controlled by the lighting timer relay, lights on will switch to higher preset fan speed.

It would be easy to adapt the circuit go to full fan speed or a third fan dimmer by adding a thermostat to override both fan dimmers as a third option to deal with high temperatures.

[attachmentid=65645]

Nice one OT1..will try it out asap! Thank you

Josser/All as a note:-

The advise above on overriding a fan speed controller with a thermostat to deal with high temperature is valid as far as it goes, in that it shows continuity of live, earth and neutral conductors. To be totally safe all terminations should be in enclosed boxes, all cables retained to the enclosures/boxes with restraining clamps.

Where the circuit becomes more complex it is easier to just show just the live path connections as a circuit diagram.

All the diagrams are for your understanding on how it works, not a guide to wiring the circuit. Under uk law it is illegal to wire and connect electrical circuits of this type unless first checked and approved by a certified electrician.

Understood.... (Ot1 imagines being blamed for jozzers growroom burning to the ground)

Cant find any mains changover relay's tho...is there such a thing or will i need to use a transformer to 12v?

Have a handy electronics engineer who can check it out for me...I been waiting for him to do this for me for a year....better to do it myself then invite him to criticise it

Jozzer we are in a time where its going to be illegal to wire a 13a plug soon. I'm retired so no longer qualified to advise, or so nanny state says.

You can get mains coil octal based relays such as omron, schrak etc from radio spares maplin etc all you need is a octal base, a plugin relay and a cover plate so you don't put your pinkies on a live terminal.

See pic:- [attachmentid=65701]

Diagram for low medium preset and full speed via thermostat:-

[attachmentid=70496]

Diagram for low medium and high preset via thermostat:-

[attachmentid=70498]

I hope this helps you in your quest.

Very elegant solutions. I wish I had asked last year now!! Will get on it imediatly....fed up of going to adjust the fan myself twice a day
Thanks!

Thanks for the new diagram ot1. I think though am I right in thinking that the fan controller will be trying to vary the power going to the thermostat this way? Doesn't seem to like it.

Cheers

From your diagram and your description the habistat acts as a double pole switch disconnecting live and neutral power out.

I show a constant live and neutral to the habistat just as it has always been connected. The switched neutral on power out should not be connected. The switched live power out overrides the dimmer when in the make position. ie it connects the two dimmer contacts together.

Its important that the mains in and the power out wires are connected the right way round.

If you have wired it as I showed it, what is not working as it should, ie what exactly is it doing?

Well the Fan seems to just come on full power with the speed controller turned off and it has no effect.

Somehow power is getting to the fan but I have no idea how. All that is connected to the fan power wise is the L1 and a neutral that is coming stright from the mains.

Somehow and for some reason the Habistat power out is giving the fan power even when the thermostat is not active (it has lights to show Device On).

Only thing I can see is does it not create a live loop between the Mains in of the Habistat and the Power out? i.e Habistat Mains in is indirectly connected to the Habistat Power out. Or does this not matter?

Thanks for your help

Remove the wire [power out] from the habistat going to L1.

Is the fan dimmer now working as it should?

Yeah I tried that earlier to see it works if the Power out of the Habistat is not connected.

The fan dimmer works without the power out connected. With the power out connected it somehow creates a loop within the habistat and lets power through even though the thermostat isn't at the correct temp??


I guess it doesn't sound good Any ideas? A relay wouldn't combat this would it if you put it between the habistat power out and L1? Thus eliminating this "loop" for when theres no power coming out the power out (relay off) and then creating the curcuit when the thermostat comes on. It would give it full power if its correct or not, if it's safe thats another question.

Wow this is a wicked thread Ot,

i've been thinking along these lines of fans slowing with lights off, i still need to get a new fan and filter in the near future(new light and contactor this weekend fan next week end), i want a RVK 150mm L1 with matching filter for extraction i already have a RVK 100mm which i want to use as intake

would it be possible to have both fans running at about 50% if it goes above 27 deg thermostat cuts in night or day and fans switch to full until temp drops, and when lights switch off the fans slow to 25%, enough to keep humidity down though and the temp constant,

i've seen a circuit similar to this but how about using more than 1 fan, could both in/out take be wire together or would it cause lots of problems having diffrent size fans would a intake hole compensate the air pressure so when the big fan is on full and the little one is not supplying as much air to the room as is been removed so would a intake vent compensate?

Ok next. What happens if the fan wire and the power out wire are removed from L1 and connected together? ie does the habistat switch the fan on and off?

Bren useing a honeywell T6360B stat you can switch up to 720 watts of inductive load, that is at least 4 mid sized rvk fans.

Doesn't like that either, power comes through but the Habistat is going funny. Do you think the neutral out of the PowerOut might have to be connect for the Habistat to work properly? I know in theory it shouldn't make a difference. Can it actually be anything else?

edit: Just tried it against it working properly, and with the neutral coming directly from the mains. With neutral from mains it give the fan power without the DEVICE ON light on, when it gets to a certain temp the DEVICE ON light comes on, meaning the actual thermostat is working, just the fan is getting power somehow.

edit again: Just tried a couple of other things, Could it be that the Habistat actually switches off the neutral and not the live? I know it probably wouldn't but just an idea.

In that case if it needs the switched neutral to work, you will need a relay as well do you want a revised drawing?

Thanks OT i was wondering more about the actuall wiring,

For what i want which i would need to use?

The diagram with 3 fsc or would the one with 2 Fsc do?

As i need both fans in and out on the same settings,

1) both fans at about 75% fan speed lights on under 27deg,

2) lights off 25% fan speed both fans

3)if temp rises above set temp at any time both fan 100%

also on you diagram you only show the brown wire (live) does the netural wire need conecting to all components use.

Also what light relay and change over relay be suitable, where can they be bought do you know cat. no. ?

is it a light relay the same as a contactor and do you need to make a home contactor for this or will a normal purchased one work like the ones uk420 shop spells or are these diffrent things ?

thanks for you pateints

Yes please ot1. I will order a relay have you got any advice on what to get? Many thanks

I already gave info on octal based relays above you can prob get a plugin 240v coil octal, a base and cover for about a fiver at maplins. Ok £6.58p

Powr Rly 240VAC DPDT JG60Q £4.29
Rly Socket 10A 8-Pin JG54J £2.29

Revised diagram [attachmentid=65809]

Bren its too complex to draw in all the lives, earths and neutrals in, but yes they need connecting to everything that needs a neutral and earth. Just extend the concept if the first drawing to cover all the modules.

If you use an hid light you need a contactor or relay to switch the light, you can take a switched feed from either the relay/contactor or time switch to control the night setting.

I don’t understand what is not clear, with each speed controller you preset to the speed you want for the period.

Edited to add, a Honeywell room stat only costs about a tenner at a good electrical wholesalers or plumbers merchants.

Thank you again ot1, greatly appreciate the time you've taken the draw them all for me. I can't see it not working after I get the relay so heres to it

Are the relays easy to wire? The live & neutral from power out will never get through the relay right? Will just be purely a "remote" switch if that is the right word?

Yes the live and neutral from the habistat only supply power to the relay coil. The relay is double pole, each pole is a change over switch, you just use one of the poles, wiring the dimmer across the dimmer with the normally open open contacts, [at no power to the coil] when the coil is powered the contacts close overiding the dommer. Its easy.

I have had a lot of members asking me for a how to diy on this, in some ways I wish I had not started to answer this question as it has evolved into something I did not mean it to.

So a few comments

Fan dimmers and the thermostat should be mounted on surface boxes, the octal relay is best if fitted in a small enclosure with an 35mm DIN rail which the plugin base just clips onto.

All the boxes can be mounted on a board. Wires from the boxes to plugs and fans should be retained with proper cable clamps or stuffing glands.

I don’t intend to take this futher or make a parts list. If anyone wants to make a diy project with pics showing how its done, fine! I will help if needed.

[attachmentid=65936]

Or point them here OT ....

RAZ

This is in no way disrespect RAZ, but all flexible cables that go external to boxes should be retained by a stuffing gland or clamp, see pic below. This stops all movement of wires connecting to terminal or the possibility of the wires being pulled out.

[attachmentid=65953]

right if someone could answeer this apart from ot as i think he's done enough

i do not have a contactor for my light at the moment only using a 250hps however i wanna get a 600 hps and another fan an run one of the systems with 2 to 3 FSC

so would i need to get 2 of these Powr Rly 240VAC DPDT JG60Q
Rly Socket 10A 8-Pin JG54J

1 for the light relay contactor built like shown in the diy contactor thread and then another for the fans like shown in pic which is fed from the light one is this right

Relay and base came today. Hopefully will have a go at hooking it up later. Just a quick question, is it ok to use 3A 3core cable for my fan? (safety first)

right if i got a had a cintactor with a co2 unit in one side and this fanspeed controler insteda of lights on the other would it work ok, with co2 first coming on 1hr after lights then releasing enough for the room then 10-15min later fans come on for 15min the nswitch off and enough co2 relesed and repeated until lights off,

would this work ? to control enviroment and co2.

can't quite understand bren, my relay works a treat and everything is working now, I also got an enclosed waterproof electrical box to put everything in, along with cable glands etc.

Just waiting till i feel a bit more awake till I do it all, been really busy with rl shit.

I was reading it's ok to use 3A cable for the fans, only reason I was asking was because of the inductive(sp?) load.

If you wanna save yourself the bother of making 1 of these look for a seller called sparky4uquads on ebay. He knocks these together for a reasonable price. I paid just under £60 for a humid/thermostat with day & night settings & a 4 gang socket.

Well true but honeywell thermostat and fan speed controller and a digi timer are only max 30 quid and simple to wire

Turned up today.My dads a sparky so im gonna show him this to see if he can knock a couple together for my homies & shit. Well worth 60 notes & i didnt av to get my hands dirty. If i leave feedback i also get 12 months warranty. Put that in ya pipe & smoke it.

The box on top is the dial to set the humidity & the digital box is to set the temps. Sweet as a nut m8. sweet as a nut.

Nice thread oldtimer1, thinking along the same lines as yourself here's a post I put in earlier this year

This picture shows an evitomental control board for a 21 light set up.
All 21 lights are controled on a single time clock (5) and switched via 2No. 4pole 25Amp contactors (2).
The intake and extract fans are controled by a thermostat (9). When the temp reaches 25C and above the fans run via a contactor (1) at 100%. When the temp drops below 80F the fans are swithed to another cotactor (7) and this in turn can be adjusted from 80% to 20% depending on the outside temp via a speed controler (4).
When the lights are off the intake and extract run on 20% and the heater circuit is then enabled. This again is set at 21C via a thermostat (6) and switches 2No. 3Kw via a contactor (8). So that the system doesn't overload, a photocell was added (10). This stops the lights and heaters running at the same time.
The whole system is fed on 25mm / 100Amp cable (11) direct from the mains and is distributed via a standard consumer unit (3).
All these parts were obtained from a local electrical wholesaler for under £300 apart from the speed controler which was supplied with the extract system.
Hope you find this intresting
Love
Arthur Lee

that is very very nice mr lee, i think i might be making a smaller version later in the yr.... wont be as sexy as yours tho....very nice indeed

jez

thats awesome lee thats the best enviro controller i have ever seen - real tidy professional looking as well.....

do you have any further info you could share on how to make one i would love to ditch mine for the same as yours.

regards

monkee

Hi guys, sorry to get this thread back alive but I have a problem. Below is a picture of a thermostat i found lying around the house, I want to wire it to a DC powered PC fan, any ideas guys?
Thanks a lot
Owain

Wow Mr Lee! I too am deeply impressed! Please, please furnish us with a wiring diagram and perhaps a list of suppliers! It makes my hotch potch of fans, timers, contacters and heaters look a bit pale (and rather frightening!).

HI GUYS
HOPE U DONT MIND ME JUMPIN IN. ALL THIS WIRIN AN ELECTRICAL IS GIVIN ME A SORE HEAD, IVE JUS BOUGHT A SUNBEAM TEMP/FAN CONTROLLER(SEE BELOW). BUT IT ONLY TURNS FAN ON WHEN THE TEMP HITS A CERTAIN LEVEL,ALSO I DONT KNO AT WHAT SPEED. BUT I NEED THE FAN ON CONSTANT FOR MY CARBON FILTER 2 WORK. I ALREADY HAV A FAN SPEED CONTROLLER SET AT LOW SPEED 2 KEEP NOISE DOWN AN WOZ WONDERIN IF I CLD USE BOTH TOGETHER, ANY IDEAS?

MUCH APPRECIATED
FRAZZY

http://www.blunt.co.uk/hydroponics-shop-uk...trol/index.html

Hi

I'm using this diagram kindly provided by OT1 to build my fan control but I'm wiring up an intake aswell as an exhaust. I'm not sure whether I need to wire both fans directly into the thermostat, or use some sort of a splitter on the cable coming from the thermostat going into both fans.

Any advice would be greatly appreciated.

BL

if you're in the UK, B&Q have most of the parts.

yep - Maplin will have the relay.- but what you could do is buy a room thermostat instead.

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This should do it. Please take care !



Did you get a base with the relay ?

Hey OT, does the fan speed controller in your diagram have power to it initially. I'm thinking of making one with a Honeywell T6360B and this speed controller below but pretty confused cos I'll have 2 power plugs! One to the honeywell thermostat and one supplying my fan controller already.

[attachmentid=129339]

Wow this is so cool! I can design whatever I may need man...

I'm just in the build, bu I have many opions.

How can I use an "ECO Technics Evolution" Digital Fan/Heater controller to be bypassed by a thermostat and increase fanspeed as the temps hover?

(Or would I be better off just making my own from scratch maybe?)

PS! I'm in 230V-land

^^^ i have the same question about a similar unit... but the unit im looking at eeds to be panel mounted and wired to sockets for equipment. If id thought the eco could be made to bypass a speedo id have got one ages ago but i guess theres no real reason why not.

actually i bet if you you follow the directions using a relay that OT1 did for OCC with his habistat cool control thermostat((which i may end up following if my current idea doesnt pan out)), and put that on the cooling output of the Ecotechnics evoloution.....it would work...better check with a spark to be sure though.