How to : Build a PID temperature control

[bobsbeer]

Thanks for your replies. On power on it shows 'lnp' in the top display and oC and pr in the bottom display. This would indicate it is set for PT100. It then changes to PV 100 and SV 0.0, then quickly changes to a flashing oooo in the top display and 100 in the bottom display. I have the probe connected through a din connector on the box rather than directly onto the pid. I think I need to dismantle the wiring and try it wired directy.

 

[tazuk]

ahhhhhhh i think some body was on about this some thing to with electrical resistance as they wanted to do wot you did :thumb:

 

[bobsbeer]

I have disconected it from the din plug and wired it directly to the pid. But the result is the same. Is there any way of testing the PT100? I can get into the settings menus and change parameters etc, but it just goes back to the flashing oooo's. Any ideas?

 

[tazuk]

have you done a google search yet to see if any body else had the same prob or sorted it :thumb:

 

[Mark1964]

Our pids were from auber instruments in the states for a tenner more you could have bought the same one and had no hassles they are pretty easy to wire up too and we use the din plug and din chassis. You need to do a search online to see how they are wired

 

[bobsbeer]

The only thing I can assume is that either the PID or the PT100 is faulty, and more likely the PID. But to be on the safe side I have reordered both from a different supplier. This time I have gone for the V model rather than the M, which is supposed to be specifically for SSR's. If it turns out the PID is ok, then I can modify the M model by removing the relay inside. Then I will have 2. But as it only cost me a £5 it's not a major loss. Just time and hassle.

 

[Pcpogo]

Question for those in the know.

I've gathered all my parts up after reading this site in order to build my PID to control the temp on my HLT.

The part I'm unsure about is the wiring for one SSR to one element and also what kind of electrical wire, amp's etc to use to wire it all up.

Any help/advice would be welcome

 

[Vossy1]

The part I'm unsure about is the wiring for one SSR to one element and also what kind of electrical wire, amp's etc to use to wire it all up.

The SSR simply opens/switches a feed for a live input to the element. That means that a separate powered live goes to the 'in' of the SSR and the out of the respective terminal goes to the element feed. The SSR then opens that feed when triggered by the PID. The element needs a separate neutral and earth feed. Regards wires, minimum 13A.
If you're at all unsure post pics it's not worth making a mistake :thumb:

Please note, terminology above may be wrong I'm not a sparky

 

[Pcpogo]

Thanks Vossy,

I'm waiting on some15amp kettle style sockets coming for my power in and out. I had ordered 10amp ones but using a quick calculation it appears that my elements would be pulling about 11.5amp hence my upgrade.

I've got some 2.5mm twin and earth cable in the garage. I think that would be heavy enough for the wiring etc.

Still waiting on my PT100 sensor. The one I've ordered has a fixed nut and a threaded part with a loose nut. I'm assuming that I can drill a hole in my Hlt and simply screw it in with a little jb weld?

 

[Doive]

Built mine over the weekend from an ebay kit, a 33 litre fermenting bucket, and a heater element ordered from Backer. As mine is a single element, I've wired it with a single power supply, fused at 13A. Internal wiring in the box for power is 1.5sqmm cable as it's short runs. If you are using a single supply, don't loop it through the PID as the terminals wouldn't be able to handle the current - I split it through a 30A terminal block. The thermocouple was connected via a two pin plug. Tested the temperature element with a boiling kettle, which showed 98C at boiling, so I'm happy.

Did a trial boil then with the element in the bucket, which worked fine. Controller seems good.

One question - the Backer element uses a 1 9/16" thread, and the supplied 'nut' doesn't seem to want to take fully on it. Anyone had this problem? Any alternative sources of ~40mm nut to secure it?

 

[Northern Brewer]

One question - the Backer element uses a 1 9/16" thread, and the supplied 'nut' doesn't seem to want to take fully on it. Anyone had this problem? Any alternative sources of ~40mm nut to secure it?

Hi Doive

I used these nuts for my Backer elements

Cheers
Andy

 

[nerobot]

I'm in the process of building a pid controlled water kettle using an arduino and an ssr. Quite easy and seems to be going well. I'm happy to give more details if anyone's interested.

 

[JonnyD]

can someone explain why the power supply for the PID controller and the inverter needs to come from a separate supply oppose to just taking it off one of the incoming for ssr's?

Thanks

 

[BigYin]

can someone explain why the power supply for the PID controller and the inverter needs to come from a separate supply oppose to just taking it off one of the incoming for ssr's?

Thanks

I can tell you why I decided to use a separate supply - although I cannot prove that this reason is valid :thumb:

The SSR is being switched on and off repeatedly by the PID - that will mean the power being drawn through the supply will be fluctuating, and I have no idea if that fluctuating draw on the power would have any effect on the PID.

Like I say, I can't prove that it would cause an issue, nor have I tried it on the same power as the SSR...

If you do try it, let us know how it goes :thumb: :

 

[thedrayman]

can someone explain why the power supply for the PID controller and the inverter needs to come from a separate supply oppose to just taking it off one of the incoming for ssr's?

Thanks

I can tell you why I decided to use a separate supply - although I cannot prove that this reason is valid :thumb:

The SSR is being switched on and off repeatedly by the PID - that will mean the power being drawn through the supply will be fluctuating, and I have no idea if that fluctuating draw on the power would have any effect on the PID.

Like I say, I can't prove that it would cause an issue, nor have I tried it on the same power as the SSR...

If you do try it, let us know how it goes :thumb: :

The main thing is, I suppose, is that the set-up works, right? Have you encountered any issues with your PID set-up during your subsequent brews BigYin?

 

[BigYin]

Happy to report that it's been smooth sailing for the PID :mrgreen:

The elements didn't fair too well on one brew where I forgot to put the water in before I switched it on... One element gave up, and although the boiler was a bit scorched it was still watertight, and the brew day continued, however I replaced the elements and the boiler before the next brew.

 

[micspa]

Ok I need some help. I have wired up my REX C100 pid and powered up. The pid turns on and then goes to a top display of flashing oooo. Which according to my instructions says is an error code for 'The wire is disconnected at Inputting, the polarity is connected inversely or above input range'. Is the inputting the PT100? I have checked the live 240v feed is correct. Or is that about the connection of the PT100? That just seems to have 1 red and 2 blue wires, which I have connected to Terminal 8 = Red wire, Terminal 9 = Blue wire and Terminal 10 = Blue wire. Is that correct? What does it mean for 'above input range'?

Thanks for your help.

You can test the PT-100 if you have a multimeter set to ohms. It should read about 110 ohms between each read wire and the blue (depending on the current temperature). Your wiring sounds right but you may need to put a bridge in between terminal 10 and 11. If you could post a pic of the terminals it might help.

 

[JonnyD]

Anyone else had the same problem as me, the pid ssr output is 8vdc and pitiful current. I had to put an interposing relay to switch the ssr at 240vac. Bit annoying as I had to wait for the relay to come from America.

 

[UpTheToon]

I'm looking into building one of these... do the Rex-c100 still appear to be the best value for money?

I looked at Auber but it's £40 now just for the PID delivered from there (plus the inevitable customs charges).

There seem to be lots of different one's on ebay and massive variances in price with some (chancers?) having listings up for £130 for what looks like idenical pid, SSR and heatsinks as £25 listings.

 

[UpTheToon]

Actually, the Sestos can be had from Amazon for £16 and that appears to be the one used by mrlard in his controller so it's probably decent.

http://www.amazon.co.uk/Sestos-Digital- ... B008GS2QFU