Two variants of DOL method – starter and controller. DOL starters are basic electrical starters with contactors and relay for ON/OFF operation and overload protection of the pump set.
The Star Delta Starter is a very common type of starter and is used extensively as compared to the other type of starting methods of the induction motor. Star Delta Starter (Y – Δ) is a common type of three phase (3 phase) induction motor starters generally used in low starting torque motors.