DIY HLT

[armedcor]

I had my auber wired up so both elements had a kill switch that way I could monitor temps etc it's definitely do able.

[BrewDorg]

This is what I have planned so. I have the PID wired up and successfully finished a brew with it yesterday evening. My next plan is to add a toggle switch to allow me control the kettle with either the PID for mashing, or a PWM for boiling and controlling the boil. The kettle boils too vigorously for my liking as is, so this could be a solution. I planned to wire it so that I can still see the temperature on the PID while controlling it with the PWM. I've also added a thermal switch for safety to prevent dry boils. Does anybody know if this could cause an issue with the PIDs tuning?

[dcalnan]

Are you putting a transformer in for the pwm?

[BrewDorg]

The one I bought is for AC so all good there.

[BrewDorg]

So I wired up my kettle this evening just like in my diagram. However, the RCD trips every time I ramp the PWM past 1/4 of the way. Anyone have any ideas why this is happening? Everything looks like it's wired and grounded correctly. PWM is the one below...

http://www.ebay.co.uk/itm/331012329594

Edit: Just realised where you meant I needed a transformer dcalnan I'll have to go get one

[BrewDorg]

Probably going to avoid the need for a transformer and rewire it like so:

[BrewDorg]

I've decided to abandon the PWM. I don't know why, but it's tripping my sockets fuse when cranked up more than 1/4 of the way. Also, I fried my SSR with all the messing around.

Instead I've bought a MYPIN TD4 PID controller. This has a manual mode which allows you to set a % on the power supplied per second. So this will achieve the same goal much more nealty, albeit more expensive.

[cruiscinlan]

Brewdorg, do you have any knowledge on the difference between the temp probes out there?  I've posted a list of them in the STC-1000 thread:

http://www.ebay.co.uk/itm/291671778727?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.co.uk/itm/172135786456?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.co.uk/itm/151803081694?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

They all appear to be the pt100 that was recommended as the most accurate one, but they range from £2.79 to £5.45 ea.