Direct-On-Line (DOL) starting – advantages, disadvantages, and applications

What is DOL starting?

The motor is connected directly to the full line voltage via a contactor and protective device.

Advantages

• Simple construction.
• Low cost.
• Easy maintenance.

Disadvantages

The starting current is high and can create severe mechanical stress.

When to use

For motors and loads where the power grid and the machinery can tolerate direct starting.