In this article, we will discuss a microprocessor (Figure 1) as part of the control circuit (Figure 2) of a medium-size commercial ice machine. Notice that the microprocessor has taken the place of a lot of the hard wiring that used to be inside a machine of this nature.
This type of technology is often referred to as "clean technology." Now, most modem control circuits consist of a microprocessor, a few starting components like a start and run capacitor, potential relay, compressor contactor, and the main loads or power-consuming devices.
In this case, the main loads include the compressor, harvest motors, hot gas and purge solenoids, and water pump. Most technicians are not afraid of the main loads or power-consuming devices when troubleshooting. It is the microprocessor that is the most feared. However, the microprocessor can actually be the simplest component to troubleshoot with a little patience, understanding, and practice.