~ When to choose a variable speed drive or soft starter~
Leading industrial motor and variable speed drive (VSD) manufacturer WEG, has released a whitepaper detailing how to choose between VSDs and soft starters. The free guide titled, Variable speed drive or soft starter will help facilities managers to make an informed purchasing decision and is available to download from the company’s website.
Solid state soft starters use semiconductor devices to temporarily reduce the motor voltage, which helps control the terminal voltage, limit the initial inrush of current and reduce the mechanical shock associated with motor start-up and provide a more gradual ramp up to full speed. A VSD is a motor control device that protects and controls the speed of an AC induction motor by converting constant frequency and voltage input power to adjustable frequency and voltage source. However, it is not always easy for manufacturers to decide which one is more suitable.
Choosing a soft starter or VSD often depends on your application. The new guide explains the applications where soft starters and VSDs are best suited, through detailed data, statistics, and figures.
The guide goes on to discuss the benefits of soft starters and VSDs in terms of performance, versatility and energy savings. As more and more manufacturers now begin to pay attention to the environmental impacts of their equipment, the guide also explains why VSDs can save more energy by presenting practical engineering know-how. VSDs are also used in applications where complete speed control is required and custom control is needed.
On the other hand, soft starters are often the more economical choice for applications that only require speed and torque control during motor start up. Additionally, they are often the ideal solution for applications where space is a concern.
“When choosing between a VSD and soft starter, several factors like the type of application, the mechanical system requirements, and costs for both initial installation and over the lifecycle of the system need to be considered,” explained Marek Lukaszczyk, European marketing manager at WEG.
“Soft starters are typically smaller and less expensive than VSDs. However, VSDs can provide substantial energy savings, which lowers the total cost of ownership (TCO), and also offers more flexible functionality. For example, in pump, fan and conveyor applications, the fully adjustable speed of a VSD is essential. VSDs can be two to three times more expensive than soft starters, so if your application only needs current limiting during startup, a soft starter may be a more cost-effective choice.”
For more information on WEG’s range of VSDs and soft starters or to download the whitepaper, visit www.weg-automation.com.
