[bo]

This is what I'm looking to do as well, but bigger. With my setup, it's 4 heat sticks, 2 for the hlt and 2 for the boil kettle, 4.5kw each, so at 230v that figures to 25 amps per stick, right? In terms of buying SSRs, does that mean I need four 25 amp SSRs, or can I get by with two 50 amp SSRs? For the total load, if I'm running the boil kettle and the HLT at the same time, does that mean the whole system will draw 100 amps? (calculations include 80% safety thinger mentioned above) Should I just never ever have both turned on?

Each of your sticks will require 20 amps, if they are truly rated for 4500 watts at that 230VAC.  I say that because you might be inclined to use elements designed for the US which is 240 VAC. Not a big deal, but the current/wattage would drop a little if you did.

If it was me, I'd use a 50A SSR for each of them. That does 2 things. It gives you a safety margin and it spreads out the heat on the heatsink(s). Plus the price difference between a 25A SSR and a 50A SSR isn't that much.

[rabeb25]

http://www.homebrewtalk.com/f170/ 

[dak0415]

Phil,
The price difference between a 25A and 40A SSR is only about $4 so I would go with 4 X 40 (one for each stick) and wire the SSR trigger wires in parallel so you will control both SSRs simultaneously.  If you try to use one 80A SSR for two sticks (doable) then you have to deal with 50 amp wiring (pia).  And yes you will need a 100A service to the shed if you want to run HLT and kettle at the same time.  Depending on your situation, you could probably run 4 25A breakers from a panel in the shed cheaper than 2 50s.

[Kit B]

http://www.homebrewtalk.com/f170/  

Thanks, Bryan.
I really should have asked you directly, before.
Sometimes I guess I feel like I lean on you, too much.

I found exactly what I needed, here:
http://www.homebrewtalk.com/f170/planned-simple-1-element-build-282527/

The only thing the diagram seems to be missing is the thermocouple connection.

I'm also struggling a bit with placement of the thermocouple.
If I buy a 4", it gets far enough into the mash to be more accurate than a 2", but it goes in far enough that I think I might be constantly smacking it with the paddle.
Not sure how to ensure proper placement...Battling with myself, over this.

[bo]

http://www.homebrewtalk.com/f170/ 

Thanks, Bryan.
I really should have asked you directly, before.
Sometimes I guess I feel like I lean on you, too much.

I found exactly what I needed, here:
http://www.homebrewtalk.com/f170/planned-simple-1-element-build-282527/

The only thing the diagram seems to be missing is the thermo couple connection.

If it was me, I'd move that switch to the input legs, so you shut down everything when it's off. In that schematic, the controller comes on as soon as you plug it in.

[Kit B]

I was thinking the same thing...Makes better sense.
But, the diagram gives me a far better starting point than I had.

[Kit B]

Any chance someone can chime in & tell me where the thermocouple gets wired in?

[phillamb168]

Any chance someone can chime in & tell me where the thermocouple gets wired in?

IIRC, you mount the SSR directly to the heatsink between a little thermal paste, like a computer CPU.

[Kit B]

Sorry, Phil...That's not quite what I was asking.
But...Thanks for taking a stab at it.

The thermocouple is the temperature probe...
Need to know how that gets wired into the circuit.

[bo]

Any chance someone can chime in & tell me where the thermocouple gets wired in?

Here's the manual on what I think he used:

http://auberins.com/images/Manual/Manual%20version%203.4.pdf 

The thermocouple goes on terminals #4 and #5 with the negative ( red lead) on #5.

[Kit B]

Sweet!
Thanks...I neglected to see that there was a manual & diagram.
Excellent!

[dak0415]

Kit,
How are you going to control the wort flow in the herms coil.  I my RIMS, I have the RTD probe in the wort flow as it RETURNS to the top of the mash tun.  The temp will overshoot a little, then go under, but stabilizes after about 5 minutes.  The wort moves all the time using a small march pump.  No worries about having the probe sticking out into the mash tun.  Having the probe positioned after the heat source prevents overheating the wort as the controller will turn off the heat source when the wort hits the setpoint and the residual heat in the kettle will keep things going.  If you put the probe in the center of the mash tun, the cycle time will probably be 4-5 minutes to affect the mash temp so the wort in the herms coil and the water in the kettle, will get WAY overheated and your mash temp will never really stabilize.

[dak0415]

PID controllers really can't deal with 4 minute lag times.

[Kit B]

Hmm...Have some thinking to do, there.

[bo]

I've never actually done this, but I would think you'd have to sense heat directly in the wort flow for there to be any real tight temperature control. .