PID Controller build

[mhewitson]

Well, having been inspired to start moving to AG, or at least extract brewing I thought the first thing I would need would be a boiler.
It's not quite finished, but I have the temp control box working and thought I would share.

The PID was a cheap (£11) Chinese REX C100 from e-bay. It came with Relay output, was two small wires soldered gave it a 12V output suitable for driving an SSR.

The SSR and Probe (a PT100) both came from e-bay, and following instructions from here and the limited manual that came with the PID it was re-programmed to accept the probe type.

The probe was connected to a Stereo audio jack to allow east removal / replacement etc.

The whole thing was built into a Maplin project box, and connected to the mains via a RCD for safety.
All the connections are crimp terminals including the kettle element connection (the pins were not long enough to interface with the kettle lead)
The element it's self came from a Argos value kettle, and was set into a 38mm hole made in an old FV (this was a temporary solution, as I plan to have the whole lot in blue mango barrels when I start using it, this was merely a proof-of-concept) the 38mm hole was too tight and had to be enlarged with a dremmel, 40mm would have been a better fit I think. I'm not sure how the difference n thickness with a blue barrel will be as it was tough o get the screws to tighten properly as it was...

The first run the power cable got rather warm, so it was upgraded to something a bit more sufficient, and thats when I put the RCD on.

So here we go...the bit you all want is the pictures!

 

[mhewitson]

I should add that there are various 'tests' in there and the final set of pictures is what I settled on...

 

[mrlard]

Looking good.

Not to sound negative but

I thought those IEC connectors are only rated to 10amps so your running them on the limit I know you can get hot conditioned ones rated to 15amp

Also I would stick a quick blow fuse to protect the PIDand do you have a heat sink for the SSR?

 

[Wild Woods]

Nice tidy build.

I'm assuming the 2nd photo below is how you finished the rear connectors with one power input and one power output as the in the first photo you would end up with unshielded live terminals that could give you a nasty shock if you plugged in the lead while the unit was powered up.

Just thought I'd check :thumb:

 

[mhewitson]

Actually I have a new connector for the input that has a fuse built in - its what the hole was cut for so will be a better fit.

Its actually got the two 'input' connectors on just now, and when I get the right connector for the output will be switching it back.
It also means theres no ambiguity about where to plug in the correct lead.

Oh - and yes, the replacements are hot condition C15 IIRC

 

[mhewitson]

The SSR is on an old heatsink from a Video card, theres a 'proper' one on the way from china.

I still have the plumbing bits to do, so its not going to get used just yet.

I appreciate the feedback and comments though!

 

[tazuk]

that is wot i use from rs never had a prob yet and it looks like tesco kettle elements too wot i use too i must say i use hot plug on kettle element :thumb:

426-468 Black hot condition chassis plug,10A
http://uk.rs-online.com/web/p/iec-conne ... 4E4F4E4526

211-4224 Black rewireable hot condition skt,10A
http://uk.rs-online.com/web/p/iec-conne ... 4E4F4E4526

 

[mhewitson]

The re-wireable plugs are awkward to do, but seem fine.
Im sure its all OK.... certainly in a 10 min test run I never saw any problems.
The Inclusion of the RCD was to alleviate any issues!....

 

[tazuk]

also i now use these heatsinks for ssr's

http://www.ebay.co.uk/itm/170802776421? ... 1439.l2649

here is one of mine spare one
viewtopic.php?f=30&t=24125

here is another one main one
viewtopic.php?f=13&t=19526

 

[mhewitson]

finally switched back to a proper 'output' power connector, however all the connectors seem to be only rated at 10A, im struggling to find power output (and the equivalent male connector) rated higher.
Any advice?

 

[Vossy1]

They do make higher rated male chassis there's a 15A one here...can't find the plug at the mo tho :hmm:

 

[hedgerow pete]

just out of intrest, i would have used this type of set up to hit the temps to mesh and boil. would the probe and controller work at a lower temp, say we set it to heat the fermentation pad under a barrel, would it do this to :hmm:

 

[Vossy1]

just out of intrest, i would have used this type of set up to hit the temps to mesh and boil. would the probe and controller work at a lower temp, say we set it to heat the fermentation pad under a barrel, would it do this to

It would :thumb: If you wanted it to cool as well you'd have to use a different type of controller, something like a ATC800 or STC1000.

 

[hedgerow pete]

just another silly one then, a pt100 temp probe reads to 400C, for my chicken incubator 50C is boiled egg time so does anyone know of a more sensitive probe but with a shorter range, i was looking at some where between 20C and 50C with 36C being the perfect temp

if you had not realised i was wondering if the temp reader controll set ups we use here can be mashed to suit a incubator running at 36C, mine at the moment is an analogue and i would like the idea of going digital, for the heater i was thinking of under floor heater cable or trace heater cable as the element rather than a asda kettle element

 

[The Goatreich]

I wish I had this kind of electronics knowledge and confidence. That's a really tidy build, congrats.

 

[tazuk]

does your boiler have you just got one element ????? just think if one goes pete tong and 2 elements can bring to the boil quicker :thumb:

 

[mhewitson]

I wish I had this kind of electronics knowledge and confidence. That's a really tidy build, congrats.

Thank you - I dont really have much skill...it was my first time doing anything like this, I had only ever done some basic soldering before.
As long as you can get your head round how the PID operates, its fairly simple to wire it all up. The crimp connectors just make it look like I know what I'm doing

Next up will be an STC1000 I think, to control a fermentation fridge.

Then I will eventually build a bigger box for PID's for HLT, HERMS and Mash tun.... All this planned and I'v not even moved to the darkside yet!

 

[mhewitson]

does your boiler have you just got one element ????? just think if one goes pete tong and 2 elements can bring to the boil quicker :thumb:

I'm not actually planning to use what I have as a boiler - I doubt the pastic would hold it. Once I get a mango barel i'll be using that, most likely with 2 elements fitted for redundancy. One on the PID and the other a simple on / off.

 

[mhewitson]

They do make higher rated male chassis there's a 15A one here...can't find the plug at the mo tho :hmm:

Cheers Vossy!

 

[tazuk]

here is how i did my twin pid unit its a shuttle pc case loads of room i have also mounted ssr's on heat sinks now :thumb: