We all have preferences in life. Some prefer Coke over Pepsi, some like ketchup more than mustard, and some even prefer Dunkin over Starbucks (New England reference…). These preferences extend into the world of manufacturing and automation as well.
When upgrading your facility to meet modern standards, it is crucial to remember that not every product will be the perfect fit for you — and that’s okay! You can find one that is.
At HESCO, we strive to provide our customers with guidance that leads to decisions that benefit their facilities, not guidance that leads to financial burdens with no end in sight.
Among the many preferences and decisions you will face comes the decision of whether a soft starter or a drive is better for you. We are going to walk you through these terms and explain why one might be a better fit, depending on your needs.
What is a Soft Starter?
In the simplest terms, a soft starter is a device that is designed to smoothly start a motor. As the motor starts up, the soft starter gradually increases the voltage for a smooth acceleration. Essentially, ‘soft’ means ‘gradual’ — slowly starting up so there is no wear and tear on the motor.
Source: Rockwell Automation
Soft starters ultimately reduce the mechanical stress on the motor, preventing potential damage to caused by any sudden rushes of power forced upon the motor.
What is a Drive?
In simplest terms, a drive is a device that starts a motor with the capability to control how fast the motor is moving, while simultaneously controlling the torque that motor outputs. A drive is almost like a sophisticated soft starter. While the soft starters only control the starting and stopping of a motor, drives control and vary the speed throughout operation.
Source: Rockwell Automation
Features of a Soft Starter
Soft starters and drives may perform similar tasks, but there are key differences that distinguish their main features. The features of soft starters vary from those you might find in drives.
Soft starters offer flexible programming options, allowing you to set the cadence of starting and stopping, according to your facility’s needs. This can be accomplished with a HIM or as simply as using Dip Switches. They come with LED display features that provide clear visibility of the run status. Additionally, they are rated for multiple voltages and environments, enabling them to withstand a multitude of voltages a motor may have, regardless of environment.
More technical features include fieldbus connectivity and modular auxiliary contact capability:
- Fieldbus is a collection of industrial computer networks and protocols that allows communication between industrial field equipment. With fieldbus connectivity, the soft starter does not need to connect directly back to the controller, eliminating the need for additional output devices.
- Modular auxiliary contact allows the soft starter to indicate contact status. Ultimately, this feature is used for remote visual signaling and alarming, ensuring you receive notification without the need to be physically near the soft starter and motor if something were to go wrong.
The features of soft starters are more complex than those of drives, as drives are more universal tools used in facilities.
Features of a Drive
Drives are a bit more complex. Similar to a soft starter’s programming, drives have multiple control modes and parameter settings. This is where you can control the cadence of how the drive is operating in the motor. Since the drive runs throughout full operation, there are more parameter settings in which you can control the speed and torque of the motor. Additionally, they are rated for multiple voltages and environments, enabling them to withstand a multitude of voltages a motor may have, regardless of the environment.
Drives, just like Soft Starters, have configured Fieldbus Network capability. Unlike Soft Starters, drives also have expandable inputs and outputs. Also known as I/O, these are useful for expanding the functionality of the drive, creating the ability to send more signaling between drives and other automation equipment without the requirement of a network.
Soft Starters v. Drives: Which to use when
After learning about the distribution functionalities of soft starters and drives, you may still be unsure of which option is better for you. Let’s walk through some key features to help you divide which one hits all your wants and needs.
Cost
We recognize that cost is an enormous part of your purchasing decision.
In general, soft starters are a less expensive option. Depending on the size of the version you are looking for, they can range anywhere from $350-$1,000+.
Drives are usually a more expensive option. The price of drives varies greatly depending on the horsepower and voltage required, as well as what application specific requirements are needed. A basic low Horsepower drive can be as cost effective as $500, but with added features and increased Horsepower, we can expect the average price to be in the thousands.
Energy
If you are looking for an energy-saving product, either option could check that box for you. Both options are known to reduce energy costs because of the efficiency of the products. Drives have the capability to reduce energy consumption further, as they have the ability to continuously run motors at speeds under 60 Hz.
Size
The physical size of the product could be a crucial factor for you, especially if you have limited installation space.
Soft starters tend to be smaller and more compact than drives. Since they are essentially stopping and starting the motor, and nothing beyond that, they don’t require the memory features seen in some drives, reducing footprint in some instances.
Drives, on the other hand, are a bit larger and take up more real estate. Since they have greater programming capability and a higher Horsepower threshold, they can be less compact.
Source: RealPars
Control
The control capabilities of these products differ significantly.
Soft starters have very limited control over the motor — only the acceleration and deceleration of the motor from start to stop.
Drives, on the other hand, control the speed and the torque of the motor at any point in operation – not just while starting and stopping.
It is important to take a step back and look at what you are truly looking for in your facility. Though the main functionality is extremely similar, it depends on what your needs are.
Soft Starter v. Drive – No Right Answer
We can’t give you a definitive yes or no answer for one product over the other because these products are highly application-specific. The guidance we provide will vary greatly depending on your current equipment, motor size, horsepower, and other factors.
Ultimately, you need to think about whether or not you want your drive to be capable of controlling the speed of the motor. If you are, then a drive would be the right answer for you. But, if you are looking for a product that smoothly accelerates and decelerates the motor, a soft starter would be great for you.
At HESCO, we aim to provide you with the guidance you need. Modernizing your facility to operate at full efficiency is crucial and we want to equip you with the tools you need to achieve that.
Contact us today so we can help you choose between a soft starter and a drive to ultimately maximize your motor efficiency.