Starting a motor can be compared to accelerating too hard after a red light turns green; everyone gets jerked around and everything goes flying. There’s nothing gentle about it and it can even hurt. With motors, it’s the same thing. If a motor starts up with too much power, too fast, it can be damaging.  Soft starters are one way to prevent violent starts. Not only do they prevent damage, but they can save money and add efficiency as well.

Relaxed Start

A soft starter’s purpose is to bring a motor up to speed gradually. Soft starters are good for basic needs, limited space, or low initial cost.  A motor needs significantly more current to start up than it does when it reaches a normal running current. This can put excessive load and torque on the motor. A soft starter can help to alleviate some of that torque and load, and draws out the process of getting up to speed. This starts the motor with a gentle foot on the gas pedal rather than flooring it. More relaxed starts can help to draw out the lifespan of a motor and attached equipment. This saves money through installation costs and downtime losses along with the costs of replacing the machinery itself.

Cut Down Maintenance Costs

Soft starters also have the potential to save you money in a number of less obvious ways. They can save by preventing penalty costs for current spikes. They can limit strain on wires and cables attached to the motor, so the costs of maintaining them goes down as well. Soft starters prevent interruptions in the plant due to power pulls; a rush of power away from one area in the plant could damage other parts of the system.

Limitations

Although soft starters are incredibly effective at doing their job, if the start-up time is too long, the starter could overheat. Additionally, they can only be used to start a system; they can’t shut down the system.  Limitations can be taken care of with appropriate sizing. If a soft starter isn’t big enough to handle the power in a motor, it can become another barrier to overcome. As long as the starter is the right size, or even over-sized, then overheating and pulling additional power during startup shouldn’t be a problem.

Soft starters are a relatively cheap way to protect your machinery. Not only do they protect the directly attached motors, but the system and plant as a whole as well. There are economic advantages in this protection, as well as a slew of other money and energy saving properties.

You may be interested in reading:

• Motor Oversizing: Does it do more harm than good?
• Controlling Energy
  
• Calculating Overall Equipment Effectiveness (OEE) [Free Template]