Control Panel (Setup)
Before your control panel can be used for the first time, a few PID controller and timer settings must be changed for it to work correctly in our setup.
You'll need to change a few settings on the PID controllers for our setup. These are one-time setting changes that are done and saved. The PIDs will remember whatever settings you enter even when powered off.
For the most part we use the default settings. There are only a few we modify:
- Sn: Tells the PID what type of temperature probe is used. Set this to 21 for all 3 PIDs to tell them that we're using RTD type temperature probes.
- Pb: This is the temperature calibration offset and is set differently for each PID based on how the specific RTD temperature probe measures. Every probe will have some error associated with it and this Pb setting is used to correct for this error. For example, if the probe measures 1 degree too high, you would set Pb to -1 to correct the error. The critical range brewers care about is typically the 140-160F mash temperature range so if possible, it's best to calibrate to a sample in this range. One way to do this is to use a known good temperature probe (such as the ThermoWorks ThermaPen) submersed in hot water along with the RTD probe. Use the difference between the two numbers to create the Pb offset and repeat for each PID controller. While RTD probes tend to drift less than others, we still recommend re-measuring once a year to make sure the RTD probe and PID combination is still measuring accurately. Note that the offset doesn't care if your PID is set to display temperature in Fahrenheit or Celsius, the offset value is simple added to whatever value is measured.
- FILT: This controls a digital filter that is used to smooth out possible noise that may exist when taking temperature readings. The default is 0 (no filter) such that the PID updates the temperature reading as fast possible. We set this to 5 to avoid oscillations between two numbers as the reading crosses over from one value to another. Higher values result in slower response time but this is not an issue in brewing as temperatures move slowly (relatively speaking).
- A-M: This controls whether automatic or manual (or both) PID control modes are allowed. Automatic mode controls the heating element based on temperature while manual mode uses duty cycle (more information). The default value of 2 disables manual mode completely and is fine for the Hot Liquor Tank and Mash/Lauter Tun PIDs. For the Boil Kettle PID this should be set to 0 so that both manual and automatic modes can be used.
To modify the settings, hold down the SET button on the PID for 3 seconds to enter programming mode. The up/down arrow buttons are then used to change the current setting. The SET button is used to advance to the next setting. Once done, simply wait 10 seconds. All settings will be saved and the PID will return to the normal operating mode
Some other settings that may be useful:
- ALM1: This setting can be used to set a high temperature alarm. As the temperature passes through this set value going upwards our alarm will sound. Useful for knowing when the strike or sparge water temperature is reached in the Hot Liquor Tank, or when we're getting close to boil in the Boil Kettle.
- ALM2: This setting can be used to set a low temperature alarm. As the temperature passes through this set value going downwards our alarm will sound. We don't use this setting in our brewing setup, but it would be useful for brewers who use immersion chillers in the Boil Kettle to know when their yeast pitching temperature is reached.
- COOL: The default setting of 10 sets the PID controller into Fahrenheit and heat mode which is perfect for most North American brewers. If you prefer to display temperature in Celsius instead, set this to 2. If displaying in Celsius you should also set the dP setting to 1 such that 0.1 degree resolution is used. (Unfortunately the dP setting has no effect when the PID is displaying temperature in Fahrenheit).
Other settings exist but these are the only ones that we find important and/or have changed from the default settings. For more information, refer to your PID controller manual.
Auto tuning is optional and may be performed on all control panels including those that were purchased pre-assembled. It is usually not required.
The Hot Liquor Tank PID can be taught the heating and cooling characteristics of your setup and be tuned to provide more precise temperature control by performing an auto tune. This sets the P, I, and D values in the PID controller. In most cases the default values will work fine so we recommend that initially auto tuning be skipped. If after the first few uses you find that the Hot Liquor Tank temperature rises slightly higher or drops lower than the temperature you set, consider performing an auto tune.
To perform auto tuning on the Hot Liquor Tank PID, do the following:
- Fill your Hot Liquor Tank with water and set the Hot Liquor Tank PID to a typical mash temperature of around 154F. (See Step 3: Heat Strike Water from our Brew Day: Step by Step article).
- Once the water is approximately 10 degrees below the 154F set temperature, set the At setting to 2. To do this, hold down the SET button on the PID for 3 seconds to enter programming mode, use the SET button to advance to the At (auto turning) setting, and then use the up/down arrow buttons to change the setting to 2. Once done, simply wait 10 seconds and auto tuning will automatically start.
- The PID will continue to fire the heating element and raise the temperature past the 154F set value, allow it to drop, and then raise it again. This cycle will repeat a few times until the PID understands how the system reacts such that it can set the proportional, integral, and derivative parameters automatically. The auto tuning process should take between 20-40 minutes but can vary based on the system size. During auto tuning the PID set value (SV) will alternate between displaying the target temperature "154" and "At" to indicate that auto tuning is in progress. Do not make any changes to the system during this time or auto tuning will not work correctly. Once auto tuning is complete the At setting will return to the default value of 3 and the PID set value (SV) will return to displaying the target temperature of 154F.
Auto tuning only needs to be performed once. If anything drastic changes about your setup, consider performing it again.
Brewers who also wish to hold wort at specific temperatures in the Boil Kettle (such as to perform hop stands at temperatures lower than boiling) may perform auto tuning on the Boil Kettle PID as well. Auto tuning is not required for the Mash/Lauter Tun PID.
If you purchased your control panel pre-assembled these timer settings will already be set for you and you may skip this section.
You'll need to change a few settings on the Omega PTC-21 timer for our setup. These are one-time changes that are done and saved. The timer will remember whatever settings you entered even when powered off.
To modify the settings, hold down the P button on the Omega PTC-21 timer for up to 10 seconds to enter programming mode. Once in programming mode, the E button is used to change the value and the P button is used to skip to the next setting. Once done, hold down the P button for up to 10 seconds to return to the normal operating mode.
The settings we use are:
- Func: Set to 'OndL" to turn the alarm on (as opposed to off) when time runs out.
- trnG: Set to Minutes and Seconds. A little red dot will light up beside both the "M" and "S" letters to the right of the timer when the correct setting is reached.
- tdir: Set to "dn" to count down (as opposed to up).
- PrSt: Set to "Off" to continue counting after power is restored after power loss. If power in the house goes out for a split second, we want to make sure to be able to continue in the same spot without having to guess how much time was left.
- FrSt: Set to "Off" to disable resetting the timer by simultaneously pressing the P and E keys. We will only be using the external reset button we installed.
- Slvl: Set to "2" to allow programming mode to be entered by holding the P key for 10 seconds (instead of 3). This ensures that we do not enter programming mode by accident.
For more information, refer to the Omega PTC-21 timer manual.
Your control panel is now ready to use. Please refer to the Brew Day: Step by Step article for instructions on using your control panel during a typical brew day.
Continue on to Building Your Brewery - Ventilation.