Finding an enclosure of suitable size for the right price (free) took a while; however, everyone knows someone and someone has one lying around somewhere.

Fortunately, our enclosure was constructed for electronics. It has an aluminum backing board that holds electronics, acts as a heat sink and functions well for common grounds.

All components should be properly grounded and protected by GFCI circuitry. If you are unfamiliar or intimidated by electricity, please find some help. You can not be too careful; especially since the process mixes wires, water, and hands! Remember, ground everything then add your GFCI.

We normally run the brewery's electronics from a GFCI protected outlet; however, I wanted GFCI inside the box in case we ever took the brewery on the road.

Power comes into the system from the cable in the bottom and powers a GFCI outlet. All other power comes out of this outlet to the system.

The front of the control panel has all the neat gizmos we look at while brewing. They are:

• Master Switch -- Turns the entire system on or off.
• Switch Box 1 PID switch -- turns the PID controller on. PID thermocouple is in the mini-exchanger.
• Mini exchanger stirrer motor switch.
• Pump switch -- turns the pump on and off.
• PID -- the Proportional Integral Derivative controls the temperature of the water in the mini-exchanger.
• Switch Box 2 Thermocouple Reader 1 -- usually in the mash tun to measure the temperature of the grain bed.
• Thermocouple Reader 2 -- usually in the hot liquor tank to measure the water temperature for sparging.
• Open -- need some other gadget for this. A lava lamp, perhaps?
• Thermocouple Reader 1 -- usually in the mash tun to measure the temperature of the grain bed.
• Thermocouple Reader 2 -- usually in the hot liquor tank to measure the water temperature for sparging.

PID

PID stand for Proportional, Integral, Derivative. Our PID is a CAL 9900 and it's the brains behind the temperature operations during the mash. We tell this device at what temperature we want the water of the mini-exchanger and it handles the cycling of the heating element. When the temperature of the water is below our desired level, a relay on the PID closes allowing power to flow to the heating element. When the desired temperature has been reached, the relay on the PID opens and power to the heating element is blocked.

The PID's relay can only handle 5 amps and our heating element draws almost 10. To get around this, we have a solid state relay that actually supplies power to the heating element. The PID is used to drive the relay which routes power to the heating element.

These little devices are typically used in RIMS systems where heating elements are almost always (or always always?) electric. Since our heat exchanger is also electrically heated, the PID makes a nifty control.