What is a direct online motor starter or direct online motor starting?
Direct online motor starting is a method of starting a motor where full voltage is applied to the motor terminals at the start of operation. This results in the motor running at full load from the outset, without any gradual acceleration or soft-start. DOL starting is usually employed for smaller motors (< 5kW) and is cost-effective, simple to implement and requires minimal maintenance.
However, DOL starting can lead to mechanical and electrical stresses on the motor and may cause voltage sags and other issues in the electrical supply network. Motors above 4Kw should be wired using a Star Delta configuration method.
What is Star Delta Motor Wiring
The Star Delta motor wiring method is used for reduced voltage starting. It involves configuring and wiring the motor in a star and delta pattern. This method allows the motor to start at a reduced voltage and current, known as soft start, minimising the voltage output. Initially, the motor starts using the star wiring connections, then switches to delta wiring after it has gained speed.
This method is commonly used in applications where the motor needs a high starting torque and power and reduces the amount of energy consumed during start-up.
The switch from Star to Delta in motor operation is typically accomplished through a timer in the control panel that allows the motor to operate at full load during the process. This change is made in a way that ensures the motor works efficiently without any damage.
The process is essential in cases where there is a requirement for a higher output than when the motor is in a Star configuration. Using the Star-Delta method helps ensure the motor can function optimally regardless of the type of load applied.
Commentaires