Screw air compressor automatic starter

Back to the startup systems. Star/delta (Y-D) is the most common system deployed in air compressors, or in industrial machines in general. It's simple, easy to understand, easy to troubleshoot and doesn't require expensive electronics. With Y-D starter we take advantage of the lower per-winding voltage when. . Here we see a typical setup of a star-delta starter: *Typical setup of a star-delta starter. There are 6 cables going to the motor (white, at the bottom) . The system always consists of 3 main contactors (big relais) in a typical configuration that is easy to recognize. The 3 contactors are: 1. Main/line contactor 2. Delta contactor 3. Star contactor [pdf]