Motor Starters and Motor Controls

Motor starters are a type of a motor controller. A motor controller governs the performance and controls the speed of an electric motor. The aspects that the controls govern are the motor’s rotation (it can choose whether it will be in reverse or forward), the speed, the torque, and fault and overload protection.

Motor starters can be configured according to its user’s preferences. These starters avoid any pressure surge in pump applications. They can also prevent jerks, avoid stress on components, and smoothly start conveyor belt systems. In addition, they can prevent belts from slipping by slowly starting up in fans with belt drives.

Furthermore, systems with soft motor starters have control over sudden starts. They are also a more stable power supply than systems without those starters. On the other hand, those starters have the capability to reduce any intermittent voltage drops, which can affect the other loads of the system.

Different Motor Starter and Control Functions

Larger electronic motors require motor starters as specialized switches. When the starters are energized, it will connect the motor to the power supply. The electricity will pass through the starter’s voltage reduction device to the motor. And then the electricity will slowly increase.

Smaller motor starters are manually operated using a switch. On the other hand, the larger versions of it are completely automatic. Also, huge starters may need circuit breakers with them if they are handling thousands of volts.

Types of Motor Starters

There are three main types of motor starters. They are DOL (Direct On-line) starting, Star-delta starting, and soft start up. Each of them has different settings that let them accomplish different functions. Here are their specifications:

Direct On-Line Starting

• Has only one switching device
• Voltage dip
• The current peak is high
• The starting torque is high
• Motor has three conductors
• Low to medium power ratings for three-phase motors

Star-Delta Start-Up

• Has two or three switching devices
• Requires more maintenance
• Mechanical stress is high
• Generates torque surges every time there is a Y to D switch over
• Mains load is high
• It has a reduced starting torque (33% of the optimal torque)
• Motor has six conductors
• Low to high-power ratings for three-phase motors

Soft Start-Up

• Has one switching device
• Has a voltage dip that is negligible
• Has no torque peaks
• Has no current peaks
• The starting torque is variable
• Motor has three conductors
• No maintenance is needed
• Have optional protective functions and guided soft stop
• Low to high-power ratings for three-phase motors

If you are intersted in finding out more about this important topic, or are unsure which motor starter or control your application requires, please contact us and we will gladly help you pick out the right component for your application.