How a Silvia Works|
On, heating up
On, at temp
Steam, heating up
Steam, at temp
Pumping hot water
Modification for PID
Dual Setpoint PID
Advanced Dual Setpoint PID
Dual Setpoint PID Wiring Schematic|
In this example we have modified the basic PID installation (seen on the previous page) with an added, advanced function. In some PIDs there is the option for dual setpoints. That means that the PID is capable of having two temperature setting programmed. The PID has two additional contacts on it that when shorted out (connected together) they select the second setpoint. When the two contacts are disconnected the first (default) setpoint is selected. This is usually used to control steam temperature.
To trigger this function merely connect a switch across the contacts. This can be an added switch on the PID's mounting box or it can be the steam switch in the espresso machine as shown here.
The wires (5) go directly from the steam switch's terminals to the external PID where they would connect to the two second setpoint terminals. Important to note here is that the original wires from the steam switch have been removed and are no longer used. These should be carefully insulated so as not to cause a short. Also note that the wires have been removed from the steam thermostat and have been connected together so that the steam thermostat is no longer in the circuit. If left connected, the machine could only achieve the set temperature of the steam thermostat and no more than that, regardless what the temperature the PID was set.
This is the easy and simple way to make this change, but the problem is that the illumination lamp in the steam switch will not function because there is no longer any AC power going to the switch.