Motor starters are devices used to control and protect electric motors. They manage the starting and stopping of motors, regulate their operation, and ensure efficient and safe functionality. Unlike simple relays that only switch power on or off, motor starters also provide crucial protection features such as thermal overcurrent protection, which prevents motor damage due to excessive current or overheating.
The primary role of a motor starter is to handle the large initial current (known as the inrush current) that motors draw when they start. This current is typically many times greater than the motor's rated current, and direct exposure to it can damage both the motor and the electrical network to which it is connected. Motor starters carefully manage the application of initial power, often through a combination of contactors and overload protection devices.
Contactors control the flow of electricity by physically closing and opening the electrical circuit, while overload relays protect the motor by breaking the circuit if the current exceeds safe levels.
Motor starters provide numerous advantages for operating engines and machinery:
The DOL starter is the simplest and most basic type of motor starter. It directly connects the motor to the power supply, providing full voltage during start-up. This type of starter is suitable for small motors with low starting currents and minimal load torque.
The star-delta starter is used for large induction motors. It employs a special switching mechanism to initially start the motor in a "star" configuration, which reduces the starting current, before switching to a "delta" configuration for normal operation.
A soft starter gradually increases the voltage and current supplied to the motor during startup, reducing the impact on the electrical system. It provides a controlled and smooth acceleration, minimising mechanical and electrical stress.
Also known as a reversing motor starter, this is a type of motor starter that allows an electric motor to be operated in both forward and reverse directions. It provides the necessary control and switching functions to change the motor's rotation direction.
Motor starters are essential across various industries, providing power and reliability. Here’s how they are applied:
RS is a trusted supplier and distributor of high-quality motor starters, featuring a comprehensive selection from top brands like RS PRO, ABB, Schneider Electric, and Siemens. Our motor starters are engineered for reliable performance and longevity, meeting rigorous standards for efficiency and ease of integration into various systems.
Business account customers who order motor starters online from RS enjoy free delivery on all orders over $40 (excluding GST), with a delivery fee of $10 for orders below this threshold. For private accounts and guest shoppers, delivery is free on orders over $80 (excluding GST), with a $12.95 delivery fee applicable to smaller orders.
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