How to set up a Sestos D1S PID controller

sestosSo, I and many others it seems, have been struggling to set up their Sestos D1S controller. It was a great buy, about £35 from ebay with a solid state relay and thermocouple. I can’t complain about that. It was also relatively easy to wire into the oven I’d made. I put this together with a load of kingspan and the internals of a domestic fan oven I’d wombed up (again from ebay) for £10. Add a project case and some other bits and wire and we’re off.   It went together and in theory powered up properly. The light on the front came on, the relay activated and the element came on. From that though, it never really settled on to a value; it would just overshoot in an unnerving way. What you’re meant to do is let it auto-tune itself (which can take a few hours) and then it should be super-lovely. What actually happens is:

  • you read the manufactures instructions and realise that the single sheet of A4 isn’t going to help. You scratch your head, you have a go at fiddling with it, and it makes no sense. So you stop.
  • Then what happens is you go googling and find a whole bunch of people who’d had issues with this (weirdly brewers and gourmets from America) and I found this far more excellent page from a chap I think is called Claes Junk. It gives great instructions about how to set up the controller, but doesn’t help with the auto tune I’m struggling with.
  • You throw your hands in the air and buy a PID from a different spot – I ebay’d PID controllers, and went looking for distance nearest first from my house. I found Simon at Harrogate Automation Controls who has a massive amount of PIDs and other magnificent bits of gear. He knows his stuff and had things like cabinets and contractors to PIDs and compressors. We spent a happy hour chatting and I came away with a new controller for an outstanding price
  • Feeling like your oven is getting a new start, you ring Warren and tell him what you’ve done, and he also reminds you that he has the same PID and his works. So, I got Warren to give me his config and I fed it in
  • Now it kind of works, but it overshoots by 10 degrees. It doesn’t overshoot and then nicely hold the new temperature, but wavers around +- 10 degrees.
  • Yo go back to Claes’ instructions and rerun the autoconfig.
  • forget you’d left it on and leave it running overnight
  • Bugger me – it works. rather than finding fire, I found a nicely working oven which was holding the temperature within 0.2 degrees.

So, for those of you wanting to configure your Sestos, do what I did and lift my config values (below) and then run the auto-config.  The ones that matter are:

 

Parameter Definition Value
df Hysteresis 0.3
CTRL Control output (3 = PID) 3
m50 Integral 100
P Differential 300
t Hysteresis time 160
CTL Control Period 10

Thus endeth the lesson