Operating the Rancilio Silvia after PID Kit Modification, Version 4

Operating the Rancilio Silvia after PID kit modification Version 4

After retrofitting the Rancilio Silvia with the PID controller kit, the espresso machine should be operated in the same manner as the original machine with the exception that you should now pull the espresso shot when the boiler temperature is within $ \pm1 $ degree of your chosen set temperature (set value or SV).

When the machine is turned on, the controller will display the boiler temperature in the machine. The temperature reading will start to increase after 30-60 seconds. As the temperature approaches the set value, you will notice that the panel light next to the power switch will start to flash. This flashing indicates that the controller is cutting the power to the heater such that the temperature will not overshoot as it approaches SV. After the temperature has stabilized within $ \pm1 $ degree of SV AND the machine has been “on” for 45 minutes, it is ready to produce espresso.

Machine No. 2, SV=104

Figure 1 shown the brew water temperature changes with time. The reason for such delay is due to the structure of the Silvia machine. The boiler of the machine has only a thin section connected to the grouphead. It will take a while for the heat in the boiler to transfer to the grouphead. In general, it takes 25 to 45 minutes to get the brew water temperature stabilized. During the warming up period, we suggest user to install the empty portafilter on the machine. After the controller stabilized at SV, run the pump for 4 to 6 fluid oz of water (120-180 ml) to flush the grouphead and portafilter. That will speed up the warming up process.

Brew Water Temperature Setting

Table 1. SV for different kit

Table 1 lists default settings for the SV of the controller.

Figure 2 Correlation between PID controller set temperature and brew water temperature detected at grouphead measured by Scace Thermofilter. Top, display in degrees Celsius. Bottom, Display in degrees Fahrenheit.

Figure 2 shows the correlation between the PID controller set temperature and brew water temperature. The controller in the Auber instruments' PID kits has been calibrated with its sensor to the accuracy of 1 degree C before shipping. However, due to the machine structure variations, the brew water temperature of

different machine can have 1-2 C difference when controlled by the same PID controller kit. For detailed relationship between the PID setting temperature and brew water temperature, please read the file named "Temperature Performance Study" in the CD that came with the kit.

It should be noted that the setting temperature we recommended is lower than some people suggested on the internet forums. As SV can be easily changed, it will up to the user to decide what the best temperature is for their espresso.

Changing Brew Water Temperature Setting

There are two ways in which SV may be changed:

1. Press the ▼ or ▲ key once and release it. The display will change from measured temperature (process value, PV) to flash the SV. Then press the ▼ or ▲ key to change SV until the desired value is displayed. There is no need to press the SET key as the display will change back to reading the boiler temperature automatically after no keys are pressed for 8 seconds.

2. Press the SET key and enter the code 0001. Press SET again. The controller will display the current setting for SV. Use the▼, ▲, and ▶ keys to change the SV to the desired value. Press the SET again. Then use the ▼ and