This is the new control panel that makes it all work. If you will notice both pumps and burners have the ability to be automatic as well as a manual override. I know how electronics can at times have a mind of their own and that is not a good thing in the middle of a brewing session.

All current comes through the Main Power switch and then is directed to the switches which control the circuits and the pilot lights. Both pumps have the ability to be powered direct or through liquid level switches (which have not been added to the system yet). The HLT burner switch sends power to one of the two Hot Surface Ignition Controllers (mounted inside and I will explain them further down this page) when in manual mode. When in automatic mode power is sent to the contacts in PID 1 and current is switched as required to maintain the temperature set point, allowing the pilot light to display burner status.

Inside the control panel box are 2 hot surface ignition control modules that send power to electronic gas valves for the burners, send 120v power to electric burner igniter coils and monitor flame sensors mounted on the burners to shut off gas is for any reason the flame would go out. These modules came from a gas fired furnace and have relays inside to switch burner solenoids, a blower fan (which is not used on my system), monitor flame status and display fault codes to be used in trouble shooting the system in case of a failure.

To allow the PID to turn these modules on and off, a 12vdc transformer is installed to allow the PID to switch a low voltage supply to turn on a 120vac circuit (burner solenoids) to the controller (there is also a 24vac transformer mounted on the outside of the box to supply the hot surface ignition controllers). Since these hot surface controls are used for furnaces, they have a proofing cycle that is performed to make sure the furnace fan works before they will turn on the gas valves. In a furnace this is used to turn the blower on for 2 seconds to clear any gas that may have settled in the chamber, once the controller sees a switch close as the blower makes air flow the controller then shuts off and prepares to power the igniters and burner solenoids.There are no fans in this brewery so to get around that, I installed a time delay relay into that part of the control circuit which makes the controller think a fan switch went from open to closed and allows the burners to turn on.  Another little glitch that had to be worked out was that these hot surface controllers operate on 24vac and normally use low pressure burners. After trying low pressure burners it was quick to tell that there were not enough BTU's to bring 15 gallons up to a boil in a reasonable amount of time. Luckily one of my friends in my local brew club donated some high pressure gas valves, but they operated on 120vac and required another pair of relays to allow the hot surface controllers to operate the valves.

Since I am operating devices off of 12vdc, 24vac and 120vac within this system, buss bars were installed in the back of the control panel to separate the circuits and eliminate several twisted connections and confusing wiring. All the LED pilot lights operate off the voltage relevant to the device they are monitoring.

A platinum RTD sensor is installed in the outlet of the heat exchanger coil mounted in the HLT and sends a signal to the PID1 to control the temperature of mash water being returned to the Tun. A second type K thermocouple is mounted about 5" from the bottom of the Mash Tun to monitor grain bed temperatures. Since the main system pump operates continuously once dough in is complete, there are no temperature variances in the mash bed and the wort is never over heated during temperature boosts.