Types and methods of starting DoL / Star Delta motors. Starting a DoL / Star Delta motor begins with the operation of a water pump. It requires electrical power to make the motor work. As for the types and methods of starting the motor, there are 3 main types of starting the motor: Direct on-line (DOL), Star-Delta, and Soft Start. This is to reduce the occurrence of various problems that follow, such as Water Hammer. What causes Water Hammer in the pipe system and what method