28 October 2008

A change in plans...

Changing plans is something I do compulsively if I feel there is some option which would be more ideal. I was wiring the last remaining components of my brewery Sunday and realized that the temperature controller for my sparge tank would not be able to switch the 3500W 220VAC heater element on and off without burning up the solid state relay inside.

My temperature controller is rated to switch a load of about 840W of power. I was planning on running my heater element on 110VAC which would drop the power down to 875W, but that is still 34W higher than the controller is designed to handle. There is probably a good margin of error on these but the more you push the limits of your hardware the shorter you can expect the lifespan to be.

All this prompted me to make my most recent purchase; a solid state relay from Watlow controls capable of switching 6000W. This will allow me to use even 220VAC if I wanted to utilize the full 3500W of the heater element. I think I'm stuck with 110VAC though, because I have totally maxed out the circuit in the breaker box... (I wonder if I could get a 40Amp breaker...).

I have been sketching all week since Sunday... planning how I will wire the remaining puzzle, how I am going to squeak another 15 amps out of a already overloaded circuit, how I will supply each component with the proper voltage without allowing power to back-feed through the other components (a surprisingly tricky feat).

Today I will grind out the details a bit more and hopefully have some good test runs of water level control... more pics to come...

A process cannot be understood by stopping it. Understanding must move with the flow of the process, must join it and flow with it.

The First Law of Mentat, quoted by Paul Atreides to Reverend Mother Gaius Helen Mohiam

-Pour one for me.