A DOL Starter is a Direct-On-line motor starter. Sometimes known as an ’across the line’ starter, this type of motor controller is used as a simple starter for larger electric motors, providing full line voltage to the motor terminals.
At their simplest, DOL Starters act as a stop / start switch for a motor, but DOL starters are often fitted with overload protection devices to prevent short circuits or the motor overheating.
Uses for DOL Starters
DOL Starters are used in a variety of applications where motor driving is required, such as running workshop machinery, large fans or water pumps.
Reversible DOL Starters
The RS Range includes reversible DOL Starters that can run a motor either forwards or backwards. These three-button starters are particularly useful for conveyor based machinery, where reversing the direction is sometimes necessary.
Ingress Protection
DOL Starters typically have a moulded plastic body designed to protect the motor starter electrical components from workplace environmental factors. The RS Range includes many DOL starter models that are suitable for the harshest work environments, which is essential when running machinery that results in a dusty environment, such as machine woodworking. There are even ATEX rated DOL starters for environments with explosive risks.
Further Security
Some DOL starters are equipped with securing functions such as key locked buttons. These optional extras are highly useful in preventing accidental or unauthorised activation of a motor, and are available in the RS Range.
What is the difference between dol and star delta starters?
Both devices are used to start induction motors however, where partial voltage is applied to each winding of a star delta starter, a DOL has 100% voltage applied. This also applies to the current, a star delta uses one-third of the starting current that a DOL does. Direct on line starters are the most common and simplest starting method, within a motor start-up they also provide the lowest temperature rise. Star delta starters allow for starting the motor at a lower voltage, making them suitable for high inertias.
