Thermostat To Override A Fan Controller

[Peter Petrelli]

Looking forward to the next project Lap, so no more blown fuses on the one your working with at the moment then?

[agent orange]

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

Can anyone tell me, in the terminals 1,3 and 4 in this diagram, is the switch coming from input 1 a SPDT contacting 3 in a N/C condition and contacting 4 when the temperature is reached? in that case, would it not be better to connect the dimmer to terminal 3?

[Laphroaig]

Teh fan controller is dead, long live teh fan controller!

Time to take the fuse killer off the wall and return it to a semblance of it's former self sans relay, thermostat, etc. Hopefully after that it won't kill any more fuses. I have purchased a shiny new 2A variac, box and a temp control to make a replacement. Just going to be a simple two speed arrangement with an additional heating circuit. Will document the build in another post.

Peace

[Laphroaig]

... et voila!

Laph's Easy Single Variac Fan Control

Peace

[lllsparkalll]

Amazing is an understatement - Youve just saved me a few quid Thanks

[plspls]

Nice one

[herbertherb]

I have seen a digital thermostat with air temp and floor sensors going cheap, could anyone help me out and tell me its specs would do the job on a controller? Its an unbranded Chinese make, but the feedback from the public is good.

Here are the specs and wiring diagram:

Technical Data:

Power Supply 220 Vac±10%,50/60HZ. (It is also compatible with 110V)

Max Load 16A

Power Consumption 2W

Set Temp Range 5°C-30°C

Relative Humidity 95%RH

Control Accuracy ±0.5°C

Work Ambient -10°C-60°C

Floor Overheating Protection 30ºC-60 ºC

Protective Housing IP20

Shell ABS+PC fire retardant

Backlight Type Green (defaulted), white or blue

Working Mode On/Off,Floating,Modulating or Multi-fuctions

Certification CE

Sensor Internal or External

Floor Sensor Rubber-thermoplastic NTC 10K

Internal Air Sensor NTC 10K

Usage FCU System,or AHU System

Programmability Non-programmable & Programmable(5+1+1days,5+2 days 4 periods)

Mounting 86*86mm & European Mounting

Note: We can also add the Network function of RS485 or ModBus, please contact us for quotation if you need it.

Main Functions:

Room Temperature Setting.

Detect and Display Room Temperature

Cool, Heat and Vent.

Manual/Auto Fan Speed.

Low Temperature Protection.

I am hoping to run this of a HQ10W Varilight V-Dim Solid State 1 Gang 1 Way 250 Watt Fan Controller.

Could someone please tell me if this kind of thermostat will work? The reason I want this one is because it can be programed at lights off.

Your advice is much appreciated.

[Laphroaig]

The control is meh, nothing special, in fact it's a bit crap, don't bother, there's allot better suited to your needs. In many ways you want it as dumb as possible, you just want a thermostat not something day, date or time aware as it's just extra hassle to program and usually more money. Most thermostats come with a normally open and normally closed terminal so they can be used for heating and cooling, from what I gather with this one it only does off and on, hence a bit crap.

The next stage up from the regular thermostats is something like the ATC-800+ I used in my control (there's a link to it at bottom of the post) thing that makes it special for us is there's a third setting, the differential. The differential is a buffer zone, set the thermostat to 23C and the differential to 2 so that your heating comes on when it falls below 21C and the fans switch to maximum when the temperature exceeds 25C. If that isn't sweet enough it doesn't then switch off again when the temperature goes back over the threshold for heating or cooling, instead it continues heating or cooling until the room reaches the set temperature 23C. It's also advisable to go for something with an external sensor as they're far more accurate and easier to position when you are not limited by having the sensor on the case.

Next up dimmer switches, it may say fan controller but it's a dimmer switch and using it will make fans very noisy. Going slowly and producing a hum that's louder than running it at full power isn't what you want. That's why most people ditch their primairs and ecotechincs controllers (they like the dimmer switch use a rheostat) and DIY something similar to what I did, you must get a variac or transformer to alter the voltage going to the fan to avoid making it hum.

Sorry to shoot down the plan.

Peace

[herbertherb]

The control is meh, nothing special, in fact it's a bit crap, don't bother, there's allot better suited to your needs. In many ways you want it as dumb as possible, you just want a thermostat not something day, date or time aware as it's just extra hassle to program and usually more money. Most thermostats come with a normally open and normally closed terminal so they can be used for heating and cooling, from what I gather with this one it only does off and on, hence a bit crap.

The next stage up from the regular thermostats is something like the ATC-800+ I used in my control (there's a link to it at bottom of the post) thing that makes it special for us is there's a third setting, the differential. The differential is a buffer zone, set the thermostat to 23C and the differential to 2 so that your heating comes on when it falls below 21C and the fans switch to maximum when the temperature exceeds 25C. If that isn't sweet enough it doesn't then switch off again when the temperature goes back over the threshold for heating or cooling, instead it continues heating or cooling until the room reaches the set temperature 23C. It's also advisable to go for something with an external sensor as they're far more accurate and easier to position when you are not limited by having the sensor on the case.

Next up dimmer switches, it may say fan controller but it's a dimmer switch and using it will make fans very noisy. Going slowly and producing a hum that's louder than running it at full power isn't what you want. That's why most people ditch their primairs and ecotechincs controllers (they like the dimmer switch use a rheostat) and DIY something similar to what I did, you must get a variac or transformer to alter the voltage going to the fan to avoid making it hum.

Sorry to shoot down the plan.

Peace

Yep, I learned the hard way. I now have a honeywell thermostat, a vent-axia 3a tranny and a flaktwoods 1.5a tranny. I will be using the above thermostat for monitoring root temps with its external probe and was going to connect it to a oil rad, but the gas is free at my grow room so may get a thermostat for the wall fitted rad. Your right the digital thermostat has no cooling switch.

I appreciate your response! Cheers!

I am now going through the wiring headache Here Just going to the G room in the next half an hour to try it out.

Edited March 24, 2013 by herbertherb

[Davey Jones]

there's a third setting, the differential.

AKA the hysteresis band

[Clay Davis]

AKA the hysteresis band

[Laphroaig]

I lerned a new wurd! Thank-you

Edited March 24, 2013 by Laphroaig

[teamdave]

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:-

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

Diagram for low medium and high preset via thermostat:-

I hope this helps you in your quest.

afternoon all.

got all my bits to build a 2 x variac with change over relay 240v DPDT (switch between Variacs) Honeywell termostat T6360 (by pass high variac to go full power) as in top diagram.

Having a few issues getting my head around wiring.

Do I run both L & N power in through my change over relay so both are switch lights on/off

Do I only need to run a live in & live out to my variacs, no Neutral?

I run a main in from junction box to thermostat via 3 core cable, brown live in Term.1, blue live out from Term.4 (to high variac) earth live out from Term.3 goes full power.

Please help, every time I think I get my head around it I get lost again

Have done a single variac build years ago and that was easy, this just messing my head up

Both my variacs are being housed in 1 large box

cheers all

[teamdave]

I run a main in from junction box to thermostat via 3 core cable, brown live in Term.1, blue live out from Term.4 (to high variac) earth live out from Term.3 goes full power.

sorry suposed to be live from Term3 goes to relay to be switched via low or high variac so guess I answered my other question about switch nuetral, no.

Still confused about feed to variacs and do they need neutral or just live in ? out.

Do I just conect the mains nuetarl in to the nuetral from my fans and nothing else?

Cheers

[teamdave]

ok thought more and now concluded

Mains comes in to terminal box, live runs to thermostat then runs back up with 2 lives (using 4 core), 1 to relay other to live conection of fans?

The live to relay is switchable between to variac, switched with a feed from light timer (live & neutral only) and is the only thing switched by relay?

I take the neutral feed from mains (in terminal box) to both variacs then return nutral from variac to fans neutral conection?

Thermostat is only thing with earth conection?

sound correct

cheers