STC bolier control? ?

[Motorhomebrew]

im just wondering is it possible to use an STC1000 to control boiler temp by putting the thermometer into the boil? or would it brake the thermometer cable??

 

[Fil]

the thermometer/probe will be fine at boiling temps.
the relay in an stc100 is rated to 10amps so if your element draws more current then it may blow the relay.

and an stc is an on/off controller . to manage a boil a power controller is more suited to the job limiting the current to maintain the boil at the level that suits you.

a simple power controller can be made from a heatsing and resistance controlled ssr using a suitably rated potentiometer to bridge the ssr control terminals to dial up/down the power output to control the boil

http://www.ebay.co.uk/itm/VolTage-R...eat-SInk-D8-/281761913583?hash=item419a519aef
and
http://www.ebay.co.uk/itm/10pcs-500...iometer-M49-/141739137527?hash=item21004f99f7

i added a amp/volt meter to mine..

 

[Twostage]

the thermometer/probe will be fine at boiling temps.
the relay in an stc100 is rated to 10amps so if your element draws more current then it may blow the relay.

and an stc is an on/off controller . to manage a boil a power controller is more suited to the job limiting the current to maintain the boil at the level that suits you.

a simple power controller can be made from a heatsing and resistance controlled ssr using a suitably rated potentiometer to bridge the ssr control terminals to dial up/down the power output to control the boil

http://www.ebay.co.uk/itm/VolTage-R...eat-SInk-D8-/281761913583?hash=item419a519aef
and
http://www.ebay.co.uk/itm/10pcs-500...iometer-M49-/141739137527?hash=item21004f99f7

i added a amp/volt meter to mine..

Looks interesting, how do you wire it up ? I added a simmerstat to my burco which tamed the boil but again is an off/on. I could replace it with the above. Can you point me to a circuit diagram ?

 

[Fil]

no circuit diagram needed just break the live wire for the element and connect each end of the cut to the load terminals of the ssr, and then bridge the control terminals with the potentiometer.

for adding a meter supply the meter with a neutral feed and a live feed from the out side of the ssr, and loop the out live load lead through the meters 'polo mint' (ferrous doughnut)

done

 

[Twostage]

no circuit diagram needed just break the live wire for the element and connect each end of the cut to the load terminals of the ssr, and then bridge the control terminals with the potentiometer.

for adding a meter supply the meter with a neutral feed and a live feed from the out side of the ssr, and loop the out live load lead through the meters 'polo mint' (ferrous doughnut)

done

Got it:

I'm guessing that I will have it outside the body of the boiler to allow the air to get to the heat sink.

 

[Fil]

Imho for a heatsink to be effective its best either in a fans direct path or exposed to the ambient environment,

i went for external heat sink mounting as it was cheaper, there are on ebay 3kw + controllers i used one of those first replacing its smal heatsink with an ex pc cpu heatsink and fan..

http://www.ebay.co.uk/itm/High-Powe...c147b21&pid=100005&rk=2&rkt=6&sd=350973315480

but the dc power supply for the fan and vent hole needed required a bigger box.

 

[Twostage]

Phil,

All the bits have arrived now 😀

Did you wire up the potentiometer using middle and left or middle and right ? I'm assuming that without the potentiometer in place the boiler would go at full whack ? If so you'd want the greatest control at the highest resistance end which would be middle and left ?

Or have I got this completely the wrong way round ?

 

[Fil]

tbh i cant recall...
i took a snap of the inside, but its not 100% clear

however i am fairly sure u can 'suck n see' without any risk of damage..

google provided ..
https://www.google.co.uk/search?q=h...FALJwtMQM:&usg=__weH911peWqR5frZYaqTKdFKb-2I=

 

[Twostage]

tbh i cant recall...
i took a snap of the inside, but its not 100% clear

however i am fairly sure u can 'suck n see' without any risk of damage..

google provided ..
https://www.google.co.uk/search?q=h...FALJwtMQM:&usg=__weH911peWqR5frZYaqTKdFKb-2I=

Just re-read the article I read about wiring it. It's a B model which means it has a linear taper so it makes no odds :-)

 

[Twostage]

Electrically assembled and tested and it works :-D

Nice blister on my thumb where I grabbed the soldering iron by the shaft:???: I always injure myself during DIY.

Now need to tidy it all up - put the controller in a box (might mount a fan on the heat sink) and drill a hole through the side of the burco to feed the cable through, sealed with a grommet. Need a knob for the potentiometer too.

 

[Fil]

Electrically assembled and tested and it works :-D

Nice blister on my thumb where I grabbed the soldering iron by the shaft:???: I always injure myself during DIY.

Now need to tidy it all up - put the controller in a box (might mount a fan on the heat sink) and drill a hole through the side of the burco to feed the cable through, sealed with a grommet. Need a knob for the potentiometer too.

good to hear

Have you considered simply mounting the heatsink externally, will save on a AC fan or DC psu and dc fan all of which will need housing in a bigger box.

a couple of DIY 2 hole lugs (tin snipped from odd copper tube scraps) circa 15mm+ X 4 to 5mm secured under the heatsink retaining screws is what i used

 

[HebridesRob]

Electrically assembled and tested and it works :-D

Nice blister on my thumb where I grabbed the soldering iron by the shaft:???: I always injure myself during DIY.

Now need to tidy it all up - put the controller in a box (might mount a fan on the heat sink) and drill a hole through the side of the burco to feed the cable through, sealed with a grommet. Need a knob for the potentiometer too.

Fancy making another tweak? I'm not going to be able to resist this when my STC1000 arrives :razz:
http://hackaday.com/2014/03/15/temperature-controller-gets-open-source-firmware-upgrade/

 

[Twostage]

good to hear

Have you considered simply mounting the heatsink externally, will save on a AC fan or DC psu and dc fan all of which will need housing in a bigger box.

a couple of DIY 2 hole lugs (tin snipped from odd copper tube scraps) circa 15mm+ X 4 to 5mm secured under the heatsink retaining screws is what i used

Used it for the first time yesterday and it worked great (still haven't got round to fitting a proper knob though). You can really fine-tune the boil.

One problem is cleaning with having both the mains cable and the external regulator attached so I've ordered a couple of 20 amp in-line connectors so I can simply unplug all the cables for easier manipulation during cleaning.

Thanks again Fil :-D

 

[Twostage]

Fancy making another tweak? I'm not going to be able to resist this when my STC1000 arrives :razz:
http://hackaday.com/2014/03/15/temperature-controller-gets-open-source-firmware-upgrade/

I think you need the STC1000+ version to programme it. Is that what you got ?

 

[ghb]

the thermometer/probe will be fine at boiling temps.
the relay in an stc100 is rated to 10amps so if your element draws more current then it may blow the relay.

You can get these controllers with a 30A relay.......

http://www.ebay.co.uk/itm/AC-220V-3...obe-MH1230A-/400706605077?hash=item5d4bf99015

 

[HebridesRob]

I think you need the STC1000+ version to programme it. Is that what you got ?

Doubt it but I don't have it yet. Made the mistake of ordering from China, which I never do since a couple of items went missing. I forgot to check, means it'll probably not arrive and I'll have to re-order. grrr.

 

[Fil]

Doubt it but I don't have it yet. Made the mistake of ordering from China, which I never do since a couple of items went missing. I forgot to check, means it'll probably not arrive and I'll have to re-order. grrr.

when u get it crack the box and if the board is stamped V1.0 reflash away

if V1.1 its less likely you will be able to reflash it unfortunatly.

if interested in remote logging the temp and status of the stc pm me for small rf board you can plug onto the reflash header pins

 

[Fil]

You can get these controllers with a 30A relay.......

http://www.ebay.co.uk/itm/AC-220V-3...obe-MH1230A-/400706605077?hash=item5d4bf99015

its a single relay version great for heating or Cooling but not able to control both concurrently.

 

[ghb]

its a single relay version great for heating or Cooling but not able to control both concurrently.

Why would you want to control the cooling in a boiler?

 

[Fil]

some folk dual purpose the brewfridge controller on brewdays