Fwiw I just completed a similar operation on my brewtus II today. I upgraded to a pid. The cost was 235 for all the parts. I had to remove the old thermowell and thermocouple and install the pid sensor. I removed the old display and the PID display fit perfectly in the old opening. I had to drill 2 holes in the base to mount the new relay. I also had to extend 2 wires that were not long enough. The kit I used had all of the screws, connectors, heat shrink tubing, and parts necessary to do the conversion with the exception of the tape dope for the thermowell. Total time start to finish was a little over an hour. The pid seems to regulate the temp much better than the old AKO controller. The temp goes back and forth between 199 and 200. The set point is 200. I have noticed that the light that shows when the pid is calling for heat is not steady, it's on and off. I'm pretty sure that helps with temp overshoot and under temp conditions. ymmv Herman
On Thu, Jan 21, 2016 at 2:29 PM, Schindler <[email protected]> wrote: > The USA distributor of AKO controllers can help with any questions > http://schindlertechnologies.com/ > > On Thursday, May 5, 2005 at 10:46:25 AM UTC-5, Doug Shannon wrote: >> >> AKO's New Temperature Controller >> >> First, I have to thank Sean for the hours he has spent on the phone >> with me discussing and guiding me through this process. If it wasn't >> for him, none of this would have been possible. >> >> Description: >> >> AKO's newest controller (model 14725) is capable of displaying 3 digits >> in degrees F up to 999F. Temperatures below 100F can be displayed in >> tenths of a degree resolution. This enables the user to set the all >> important offset parameter in tenths of a degree. The new controller >> accepts a J or K type thermocouple allowing for faster response times >> as compared to the stock controller RTD type sensor. >> >> The size of the controller (due to having 3 digits) is slightly larger >> than the stock controller which will require a somewhat bigger panel >> cut out. Although tedious, the current cut out can be made the correct >> size with the use of a dremel tool. The width of the current cut out >> needs to be 1/2 in. wider and the height needs to be increased by 1/8 >> in. There are no depth issues. >> >> You can see a picture of the 14725 on the brewtus group under user >> folders/Doug. >> >> Programming and Connections: >> >> I connected a common household extension cord to the power terminal of >> the controller. This allowed me to take my time programming the >> controller without fear of it affecting the operation of the brewtus. >> Once the controller was programmed which was a simple process by the >> way, I connected it to the brewtus using the same wires used to connect >> the stock controller. There are a total of 4 wires (power, sensor, >> relay, and common). As recommended by Sean, I used a 30 ga. K type >> sensor installed in the brew boiler's thermo well along side the stock >> sensor in order to hold it in place. As compared to the RTD stock >> sensor, the K type has greater accuracy and much faster response. >> Finally, I temporarily installed another sensor in the thermo well so >> that, using my Fluke 54, I could test the accuracy and response of the >> new controller. >> >> Initial Testing Results: >> >> After all connections were made and verified I plugged the brewtus' >> power cable into the wall, took a deep breath, and flipped the power >> switch with my barely controllable trembling hand. At this point, I had >> Sean on the phone who was intently listening for explosions and looking >> south outside his office window for mushroom clouds. Thankfully, there >> were none. The controller powered up and called for heat. Once the >> steam boiler reached 1.2 bar the temperature display began it's rise. >> Once it reached my set point of 203F, the heat light went out. But, oh >> no, the temperature display kept rising! The fluke display kept rising >> matching the readings from the controller. What could be wrong? The >> stock controller never rises above the set point! There must be >> something wrong with the controller, I thought. I certainly didn't >> program it incorrectly and if I did it would have been Sean's fault, >> not mine (hehe). After verifying the programming was correct and >> apologizing to Sean we decided to re-connect the stock controller and >> compare it's readings to that of the fluke. Our eyes were opened! The >> stock controller display would dip to 94 causing a call for heat. At >> this time, the fluke read 94C and then started to climb back to 95C as >> it should but alas, it kept rising all the way to 99C. That's an 8F >> temperature swing within the boiler but the stock controller's >> display never rose above 95C! Based on this information, we suspect >> that AKO specially programmed the stock controller for Expobar so that >> it would never show readings above the set point which gives the >> impression that the controller is doing a much better job at >> controlling boiler temperature than it really is. The new controller >> doesn't do this. It truly shows the actual temperature, whatever it >> may be. >> >> After watching many heating/cooling cycles on the stock controller and >> determining there is on average an 8F swing in boiler temperature, I >> re-connected the new controller and continued testing. Upon watching >> numerous heating/cooling cycles, I determined that, on average it was >> able to control boiler temperature to within a 4.5F range - ½ that >> of the stock controller. I believe this is due to the difference in >> resolution between degrees F and degrees C as well as better >> electronics, faster probes, and the ability to set offset in tenths of >> a degree. >> >> How did all of this affect brew temperature variance and average? >> Here's a comparison between the two controllers. First, let me >> outline the testing parameters: >> >> Warm Up Time: 2 hours >> Tested only 1st shot of the day (this is because I only brew one shot >> in the morning then one at night) >> Coffee used: vivace vita >> Shot volume: 1.5 oz. >> Shot time: 25-30 sec. >> Tamp pressure: 40lbs. >> Flush routine: 1.5 oz. flush, 1 minute to dose/tamp, 1.5 oz. flush, >> immediately pull shot. >> Target Brew Temp: 203F >> >> Stock Controller: >> >> Brew Temperature Variance: 1.2F (readings taken from the 10 sec. on as >> per Schomer) >> Average Brew Temp off target: +- .8F >> >> New Controller: >> >> Brew Temperature Variance: .7F (readings taken from the 10 sec. on as >> per Schomer) >> Average Brew Temp off target: +- .2F >> >> picture of a brew temp graph for the new controller is available on the >> brewtus group under user folders/Doug >> >> It should be noted that the time in which you start the shot within the >> heating/cooling cycle will greatly affect average brew temperature. If >> you start the shot just as the controller heats up to the set point you >> will get the results seen above. However, if you start the shot during >> the cooling phase or just before the controller calls for heat, your >> average brew temperatures will be off as much as minus 2F. >> Unfortunately, this is the Achilles heel of these controllers. It would >> take installing a PID controller to eliminate this problem. The AKO >> controllers are really just glorified thermostats. Their operation is >> analogous to a car approaching a stop sign at 60 MPH. It waits until it >> reaches the stop sign before applying the brakes causing sever >> overshoot whereas a PID controller is analogous to that same car gently >> applying the brakes as it approaches and actually stops at the stop >> sign. Sigh. >> >> In conclusion, I feel the new controller although falling way short of >> a PID controller, offers the following improvements over the stock >> controller: >> >> 1. Displays 3 digit degrees F >> 2. Faster more accurate readings and response time >> 3. Ability to program offset in tenths of a degree >> 4. Offers improved temperature stability >> >> Questions and comments are welcome. If enough people are interested we >> can put together a group buy. I will glady put together an installation >> manual for the group if there is enough interest. >> >> -- > You received this message because you are subscribed to the Google Groups > "Brewtus" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/brewtus. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Brewtus" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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