Simple PID setup/how-to

[subfaction]

Hi Guys,

I've decided it's time for an upgrade, to make brewing quicker and easier... also more things to play with...
I'm planning on using a solar pump to both recirc the mash, and whirlpool when chilling.

The twist is I was thinking that if I incorporate this into my existing Buffalo 40l BIAB system I should have something RIMS like with a PID to control the element.

I've still got the filters and plumbing to figure out, but I'm struggling to find an easy to follow guide to wiring a simple PID box, obviously with a SSR & heat sink, to just control the Buffalo. The search on here doesn't seem to like short terms like PID, and google finds me plenty of American over complex examples, so I'm struggling.

Can anyone point me in the direction of an easy to follow build guide?
Also is it a bad idea to control the buffalo with a PID, can it damage the element by cycling?

many thanks

.sub

[AnthonyUK]

A PID is a very basic circuit.
Take the power IN to the PID, the neutral split direct to the output (shown in blue) and the live via the output of the SSR (black).
To split the power I stacked two crimp tags, in/out on the PID.


A PID is fine for switching something as analogue as an element.

[subfaction]

Thanks I think that makes sense
In terms of wiring would chopping up a standard 13a plug extension cord be sufficient (I did this for my fv fridge control so have spare wire left), or do I need something more substantial?

[Belter]

Depends on the size of the wire and demand of the element

[themadhippy]

why not fit the pid and ssr in the base of the boiler.

Also is it a bad idea to control the buffalo with a PID, can it damage the element by cycling?

Aint had a problem yet.

[AnthonyUK]

Thanks I think that makes sense
In terms of wiring would chopping up a standard 13a plug extension cord be sufficient (I did this for my fv fridge control so have spare wire left), or do I need something more substantial?

Most elements by their nature are going to be high current devices so you should be using at least 16mm flex which has cables of approx. 1.5mm² conductors.
Fridges have a much lower current draw so 13A will be fine.

[subfaction]

I really appreciate the help chaps

why not fit the pid and ssr in the base of the boiler.

I've seen your conversion, impressive!

I'd love to but I don't have the tools to cut nice holes for the various bits. I'm thinking by building a separate box I can use it for other things if required, who knows where this hobby will take me next, I didn't think I'd ever go into all grain when making my first kit up, now I'm looking at RIMS, pumps, camlocks and PID's!

AnthonyUK - I take it that diagram allow me to turn off the element, whilst still getting the PID temp readout? Would simply turning off the Buffalo switch would do the same thing?

How does this kit sound:
PID:
http://www.ebay.co.uk/itm/PID-Digital-T ... 1c313b2f13

Heatsink:
http://www.ebay.co.uk/itm/SSR-Heat-Sink ... 19dd29b1a5

Cable for connections:
something like this?
http://www.screwfix.com/p/6243yh-1-5mm- ... grey/45351

Switch:
http://www.ebay.co.uk/itm/ON-OFF-Round- ... 3cce81c4fe

[AnthonyUK]

I've updated the diagram for clarity and added a switch but you could also just turn the Buffalo off or turn the thermostat right down which I think is also off.

You list of bits looks fine.
I used 16mm flex from Wilkinsons, a meter or two will do. - http://www.wilko.com/power-cables+speak ... 192c214a12

[themadhippy]

I'd love to but I don't have the tools to cut nice holes for the various bits

nice holes? i just made the origanal holes in the boiler a bit bigger.Drill,jig saw and a decent blade are about all you need.

Cable for connections:
something like this?
http://www.screwfix.com/p/6243yh-1-5mm- ... grey/45351

no,1.5mm 3 core flex is wot you want,and dont forget the cable glands on the box

[subfaction]

Thanks guys that's a lot clearer
I'm going to go for a separate box for now, although I'm tempted by the all in one result!
Just one last thing to sort now... How big a probe should I go for?
viewtopic.php?f=6&t=59928

[subfaction]

couple more questions, and I think I'm set:

What fuse rating for the mains connection?
Am I correct in thinking I need a 40A relay for the Buffalo?

thanks

.Sub

[themadhippy]

What fuse rating for the mains connection?

13A fuse in the plug should be enough

Am I correct in thinking I need a 40A relay for the Buffalo?

I used a 25A on mine

[AnthonyUK]

The PID you linked to on ebay includes a 40A SSR

[subfaction]

Great, I noticed most of the bundles on eBay come with a 25a, so if that's sufficient I'll save some ££'s

Thanks again guys!

[subfaction]

Right, this weekend is planned build day, I've got all the parts I need now just need to stick it all together

This is the wiring diagram for the Sestos PID I ended up with:

Can anyone confirm that the following diagram looks correct:



Also I'm planning on using an old CPU heatsink, which comes with an attached 12v fan, can I simply wire this into the SSR control (8 & 6) without causing problems?