UK420 > Help Needed Wiring Heater To Thermostat

Smiler

Feb 20 2005, 06:14 PM

Does anyone out there know if this is possible / safe ?

I have just bought a small, 1 foot, 60 watt tube heater for my shed based grow box. The box runs at 75 degrees ish with the 250 watt HPS on, but temps drop way down in the dark cycle - hence the heater.

I want to mount this inside the box, with a thermostat to control it when the temps drop too low. I dont just want to run it on a timer as temps will obviously go up in the dark cycle when summer gets here at last.

I have a central heating type wall mounted thermostat, which I got for a few quid, but now that I've got it I cant figure out how it should be wired up as I am largely clueless when it comes to mains electrics and am keen not to blow myself up.

I attach a pic of the stat with it's cover off, two wiring diagrams (one on the inside of the stat cover & the other the 'instructions' it came with) and a pic of the heater.[attachmentid=31098][attachmentid=31099][attachmentid=31100][attachmentid=31102]

I know I can get a plug in thermostat (pic attached) but would like to use what I've got 'cos I don't want to have to shell out another £18 + £10 P&P if I can help it.[attachmentid=31104]

Any clued up sparkys out there ? All help gratefully received.

Smiler

russ

Feb 20 2005, 11:14 PM

howdy dude, im new around here so hello!

thermostats are just temp controlled switches, looking at the diagram, 4 and 5 represent irrelevent parts of a central heating system, 2 and 3 are the normally on and normally off terminals, all you need to do is run your neutral and earth on the heater directly to the power source, and the live through terminal 1 and out of 2 or 3 into the power source. the diagrams dont seem to show clearly whether 2 or 3 is normally off, which is what you want. ie when the temp gets too low the stat will turn the heater on. so you just need to figure out which is which! try wiring it one way, and turn the stat right up, if the heater is on you know its the wrong way round.

QUOTE(Smiler @ Feb 20 2005, 06:14 PM)

Does anyone out there know if this is possible / safe ?

I have just bought a small, 1 foot, 60 watt tube heater for my shed based grow box. The box runs at 75 degrees ish with the 250 watt HPS on, but temps drop way down in the dark cycle - hence the heater.

I want to mount this inside the box, with a thermostat to control it when the temps drop too low. I dont just want to run it on a timer as temps will obviously go up in the dark cycle when summer gets here at last.

I have a central heating type wall mounted thermostat, which I got for a few quid, but now that I've got it I cant figure out how it should be wired up as I am largely clueless when it comes to mains electrics and am keen not to blow myself up.

I attach a pic of the stat with it's cover off, two wiring diagrams (one on the inside of the stat cover & the other the 'instructions' it came with) and a pic of the heater.[attachmentid=31098][attachmentid=31099][attachmentid=31100][attachmentid=31102]

I know I can get a plug in thermostat (pic attached) but would like to use what I've got 'cos I don't want to have to shell out another £18 + £10 P&P if I can help it.[attachmentid=31104]

Any clued up sparkys out there ? All help gratefully received.

Smiler
[right][snapback]311378[/snapback][/right]

Smiler

Feb 21 2005, 07:55 PM

Hey Russ - welcome to the boards. Bit of a rare visitor myself here too.

Well, after scratching my head for hours, you have come up with the solution 1st time for me.

I have wired the stat up as you suggested and it works great - it was 50/50 whether I got the right terminal and, couldn't you guess, I got it back to front initially. Swapped terminals though & everything works fine.

I am posting a photo (before I wrap everything with insulating tape) & a diagram just in case anyone wants to use this idea.

[attachmentid=31180]
[attachmentid=31181]

I stripped back about a foot of outer insulation from the heater wire and then cut down the positive to about 2 inches & wired it to terminal 1. I then took a foot of brown wire I had lying about & wired it to terminal 3. All loose ends were then fed through the stat casing to a terminal block & wired to another 3 core cable attached to a plug.

Bingo.

Thanks M8, I owe you one.

Smiler.

dikki

Feb 21 2005, 08:13 PM

Nice 1 smiler!
even I could do that with those instructions

dikki

the cityzen

Feb 26 2005, 10:42 AM

nice one chaps im going to try it with the contacts reversed and run my fan off it, that way when the temp hits 85 the fan should come on no more worries cheers

russ

Feb 27 2005, 03:41 PM

just a note cytyzen- make sue you get a stat with a double throw switch, it should say "SPDT" somewhere.
single throw ones will only switch a heating device!

the cityzen

Feb 28 2005, 11:11 AM

cheeres russ ill do that im having trouble with heat that should solve it mate nice one