Soft Start Compressors – What You Need to Know Before You Buy

Are you in the market for a soft start compressor and need to learn more before you take the plunge? Well, you’ve come to the right place – because today we are going to get up close and personal with soft start compressors and explain everything you need to know before you buy.

So what exactly is a soft start compressor? Well, it’s a compressor that gradually increases its output after turning it on. This is done to reduce heavy spikes in demand on the load and protect overheating in your motors and wiring. Not only does this reduce maintenance costs and increase the life span of your motors, but it can also significantly reduce your electrical bills. With this valuable information in hand, let’s explore the many aspects of soft start compressors and figure out what you should know before buying.

Quick Review

A soft start compressor is an electrical device that can reduce the start-up current of a motor. By adding resistance in circuits, the compressor allows for the motor to gradually accelerate, reducing the risk of damage caused by sudden shock loading.

What is a Soft Start Compressor?

In many industrial settings, soft start compressors offer users a more efficient and cost-effective operation than regular start compressors. A soft start compressor is designed to decrease the amount of electricity it consumes when brought up to full speed and load. This type of compressor typically uses a variable frequency drive that adjusts the motor’s speed in order to carefully bring the motor up to its rated load before initiating full speed operation. This gradual ramping up of power helps increase equipment efficiency while reducing time required for ramp-up as well as energy costs connected with the initial startup phase.

The debate revolves around whether or not soft start compressors offer long term energy savings or if these lower energy costs for initial startup are not enough offset the compressor’s increased upfront costs and, often times, its slower ramp-up speeds. Those in favor of soft starters argue that their upfront requirements are easily balanced out by their longterm benefits due to lower operational costs and better mechanical performance of the equipment. In contrast, opponents claim that regular/non-soft start compressors will generate just as much energy savings when given continuous use and proper maintenance.

After weighing both sides of the argument, it is clear that having a soft start compressor may have certain advantages depending on the situation. A careful analysis should be conducted in order to determine if investing in this kind of system pays off.

The next section will explain in detail how soft start compressors work and what components they consist of.

How Soft Start Compressors Work

Understanding how soft start compressors work is essential to choosing the right type of compressor for a given application. Soft start compressors utilize an electronic circuit to support the starting process, allowing the motor to gradually increase its speed and arrive at a full-load working condition in a controlled and consistent manner. This is beneficial as it helps to reduce inrush current, amperage draw, and voltage drops which could otherwise be damaging to the compressor’s performance and life expectancy.

Soft start compressors can also provide flexibility when it comes to controlling different capacities of delivery capacity by acting as a throttle on the motor, helping with accuracy and precision when dealing with small volumes or intermittent use. Additionally, many soft start compressors are equipped with a torque control to allow for smooth startups in both large and small capacity stages.

However, there are some drawbacks to utilizing soft start compressors including the potentially higher cost associated with installing the extra electrical circuitry required for them. Also, depending on the application where they’re used, such as elevated temperatures or areas of higher load demand pressures, efficient operation may not always be achieved as these conditions can affect electrical circuit components as heat increases.

Overall, understanding how soft start compressors operate is essential for making sure that you buy a motor controller that accurately matches your needs. With that said, let’s take a look at motor starting – the next important step in selecting the best compressor for your application.

Motor Starting

When it comes to motor starting, soft start compressors provide a gentle start up process that significantly reduces the amount of wear and tear on the motor by avoiding immediate electrical overload. Instead, these motors are brought up to their full speed in phases, taking several minutes and reducing the peak current draw by as much as 80 percent. This extended ramp time also helps subdue system pressure spikes, vibrations, noise levels and electrical resonances that would otherwise occur with instantaneous startup.

Fortunately, unlike hard-start compressors that require external mechanical intervention for scalability, such as disconnecting or connecting leads to different resistances in a switch cabinet, soft start solutions allow users to change the motor starting characteristics via programming rather than physically altering the electromechanical components. Additionally, these compressors are often smaller in size and weight when compared to standard counterparts due their reduced capacitors and wiring needed. This can result in cost savings when transportation is a factor.

On the other hand, some experts caution against selecting soft start solutions without first understanding the tradeoffs that come along with its longer ramp times. For applications requiring more than 150 horsepower (HP), these motors can take upwards of 10 minutes to reach their full torque output; therefore, if high-speed operation is required for short duration intervals this could lead to undesirable delays in production cycles. Moreover, despite their compact form factor and cost-efficiency benefits those same characteristics can make them susceptible to overloading during rapid starts or harsh environmental conditions which can be difficult to detect until it’s too late. Consequently, it is essential for potential buyers to understand both the advantages and potential limitations of soft start compressors before committing to an investment.

Overall, understanding how soft start compressors operate and its implications for specific applications can help prospective buyers reduce costs associated with long-term maintenance and energy operations down the line. The next section will explore in greater depth why consider investing in soft start compressors by highlighting its many benefits compared to standard contactor-based systems.

Crucial Summary Points

Soft start compressors provide a gentle start up process, which significantly reduces the amount of wear and tear on the motor by avoiding immediate electrical overload, and also helps reduce system pressure spikes, vibrations, noise levels and electrical resonances. They can be programmed rather than physically altered for scalability, often smaller in size and weight compared to standard counterparts, although long ramp times for applications with more than 150HP can cause delays in production cycles. With consideration of potential limitations such as overloading during rapid starts or harsh environment conditions, soft start compressors can help reduce costs associated with long-term maintenance and energy operations.

Benefits of Soft Start Compressors

When it comes to air compressors, soft start compressors offer a number of benefits that can be extremely valuable. Many commercial and industrial operations rely on these unique compressors in order to get consistent and reliable operation and power protection for their devices and motors. Here are some of the key benefits you can expect when you choose a soft start compressor:

1. Increased motor life: Soft starts help protect your motor from overloading and damage due to sudden start-up surges. This is because a soft start compressor can limit current inrush to around 25% of its running current, helping protect the motor from overload, resulting in lower maintenance costs down the road.

2. Better power delivery: These types of compressors also deliver a more even flow for pressure operations, which makes them ideal for sensitive operations where water, chemicals, or other materials need to be delivered at an even rate. In addition, they generate less heat, which can reduce noise levels during operations.

3. Lower energy costs: The increase in efficiency offered by soft start compressors also helps minimize energy costs, making them an ideal choice for businesses looking to reduce their carbon footprint while saving money on energy bills.

On the flip side, there are some downsides associated with using soft start compressors that you should consider before investing in one. For instance, they cost more upfront than traditional compressors, and they require larger panels and additional wiring due to their nature as variable frequency drive systems.

All things considered though, there are many advantages that come from using a soft start compressor compared to traditional units, such as longer motor life, better power delivery, and reduced energy costs. With this information in mind then, let’s move on to the next section about Power Protection and Prolonged Motor Life.

Power Protection and Prolonged Motor Life

Soft start compressors provide power protection and promote motor life by allowing motors to be gradually brought up to operating speed. When a motor is started quickly, known as direct-on-line (DOL) starting, the current drawn can be four to seven times greater than the normal running current. This is because the motor requires more current to accelerate from rest due to the inertial torque and resistance that opposes its acceleration. By starting the motor slowly and providing a reduction in voltage during start-up, soft start compressors allow for reduced peak current draw, reducing the risk of damage caused by DOL starting.

This power protection limits electrical circuit damages, saves energy, and prevents potential equipment malfunctions from occurring. Delayed starting thus reduces the starting time of these high inertia loads – further increasing motor life by dissipating heat quickly. As an additional benefit, soft start compressors also eliminate mechanical stress on other components such as belts and couplings by letting them synchronise at low speeds.

The debate on whether soft start compressors are essential for every application is ongoing. While they come with a higher up front cost than traditional starters, they are worth considering if electricity costs are high or elevated levels of ambient temperatures exist. Whether they are implemented or not generally depends on factors such as system economy, availability of components and complexity of the design.

Despite the debate around this topic, it is clear that soft start compressors offer important power protection benefits which help to prolong motor life. Looking ahead towards applications of soft start compressors is thus an exciting area to explore in order to find out just how versatile these machines can be for everyday tasks.

Applications of Soft Start Compressors

Soft start compressors offer users greater precision and control over their compressed air systems. This technology provides various applications in a variety of industrial settings, such as machine shops, woodworking, chemical plants and more. Through these uses, soft start compressors can reduce maintenance costs, minimize downtime, and improve production efficiency.

Start Soft Control Benefits:

When switched on with soft start motors instead of normal starting methods, compressors experience gradual voltage ramp-up instead of the traditional quick spike of voltage. This smooth increase in voltages has many potential benefits depending on the application. Reduced wear and tear can prolong the life of the compressor, while noise reduction makes it preferable for certain locations that may be sensitive in that respect. Additionally, there is greater protection against power spikes or outages which can otherwise lead to premature failure.

In large industrial plants, multiple starters can be connected together to form a “multi-drive” system for convenient one-stop shut down of all compressors at once during an emergency stop or shutoff. This can reduce overall energy consumption by decreasing motor inrush current from single starters compared to having separate drives for each motor.

Cost Considerations:

However it is important to note that although these soft start compressors tend to come with higher up front costs than regular starters, they are often able to provide better performance and cost savings over time when looking at total cost of ownership (TCO). Energy efficiency resulting from reduced current draw in multi-drive compressor banks yields easily calculable cost savings due to lower electricity bills that offset the higher acquisition costs over time.

With these considerations in mind, applications for soft start compressors have become increasingly common due to their ability to increase safety, efficiency and reduce long term operational costs for any facility utilizing them—all making them worth the investment in most cases.

Next Section:

Now that you know about the many advantages of using soft start compressors, we will discuss what else you need to know before buying these products for your compressed air systems.

Compressed Air Systems

Compressed air systems are becoming increasingly important in today’s industrial processes. Compressed air is a form of energy, which saves both time and money while producing highly efficient results. Compressed air systems utilize the power of compressed air to deliver the right amount of pressure to complete various tasks, such as cleaning and moving material around a factory floor. Compressed air systems, however, can be complicated and difficult to manage. Proper maintenance is key to ensuring that these systems run safely and efficiently.

On one hand, many industries have seen tremendous efficiency gains when leveraging a compressed air system due to its ability to reduce energy costs. Compressed air systems maintain the proper pressure for a variety of applications, streamlining operations thanks to the precise output of compressed air. Additionally, the proper installation and attention guarantees a long life expectancy providing improved productivity levels over time without major maintenance or repair costs.

On the other hand, there are some drawbacks associated with compressed air systems. As previously mentioned, regular maintenance and monitoring of these systems are essential for their optimal performance and extended life span. Operating with improper settings or incorrect pressures can lead to risks such as explosions or fires due to overpressure or underpressure scenarios in the system. Moreover, if not properly installed and maintained, significant costs for repairs or replacement may increase your overall expenses.

To ensure that your compressed air system runs optimally and safely, it is important to invest in reliable soft start compressors that provide flexible operation modes based on user feedback and expected operating conditions. Up next we will discuss the advantages that soft start compressors have on settings and operation modes so you know exactly what you need when deciding which compressor best fits your needs.

Soft Start Compressor Settings and Operation Modes

Soft Start Compressors offer settings and operation modes that can be customized to suit many applications. These settings are used to increase compressor efficiency while maximizing cost savings and the life of the system. Many of these settings can be adjusted manually, while others may be controlled by an automated controller.

One aspect of these adjustable settings and operation modes is the start type of the compressor. There are two primary types of starts available: soft start and direct on line (DOL). Soft starts reduce motor stress and amp draws during motor startup so electrical systems are protected from power spikes. DOL starts have faster reaction time, but cause considerable load on electrical systems which may lead to increased energy consumption or require more frequent maintenance.

In addition to start type, other factors such as speed, pressure, temperature, humidty, and motor acceleration may be adjusted or monitored in order to optimize a compressor’s performance. For instance, increasing motor speed to match the desired load reduces energy use but increases wear and tear on mechanical parts. Similarly, adjusting pressure levels can affect both energy savings and maximum flow rates for operations with varying air demand profiles.

Settings and operation modes also work together to ensure patient safety and reliability with compressors in medical applications. Air purity must be maintained in order to prevent any issues during treatment or surgery; therefore, features such as built-in filtration systems and alarms should be evaluated when purchasing a soft start compressor. The ability to quickly detect changes in pressure or temperature thresholds provides additional peace of mind that the compressor is operating safely and efficiently.

Finally, it is important to note that even with advanced settings and controls if regular maintenance is not performed then compressor performance will inevitably suffer over time. To maximize efficiency and reduce energy usage, customers should consult with experts on proper maintenance practices before purchasing a soft start compressor.

Conclusion: With a wide range of adjustable settings that impact electricity usage, mechanical strength, air quality control, quick response times, automatic monitoring capabilities – its no wonder why Soft Start Compressors have become popular for many applications today. In the next section we discuss the importance of understanding the costs associated with deploying Soft Star Compressors in various scenarios before making a purchase decision.


In conclusion, soft start compressors are an important component when it comes to regulating energy usage and preventing motor overloads. While there are many options available when choosing a compressor, it is important to assess both the features and needs of your operation in order to decide which type would be best suited for your application.

Each type of compressor offers varying benefits and drawbacks. For example, single phase compressors require more energy than three-phase units, but cost less up front. On the other hand, three-phase compressors require less energy overall but are more expensive up front. Therefore it is important to consider the long-term costs associated with each option before making a purchase decision. Additionally, soft starts can also provide increased safety against motor overloads and lengthen the lifespan of certain motors by providing a gentle ramping up of load over time.

Overall, soft start compressors present a number of advantages when compared to traditional models. By enabling gradual acceleration and deceleration for the compressor motor, these units can help reduce unexpected downtime related to extreme temperature changes or mechanical breakdowns, as well as potential risks from electrical overloads due to sudden increases in power consumption. They also offer increased protection for sensitive electronic systems and can improve the efficiency of your overall operation thanks to their ability to reduce both surge demand and energy consumption. However, while they may be convenient because of their easy set-up and installation, they come at a higher cost than other types of compressors initially so it’s important to weigh the options before making a purchase decision.

Frequently Asked Questions and Explanations

How does a soft start compressor work?

A soft start compressor works by gradually increasing the voltage applied to the motor. This gradual increase prevents a sudden surge of power, which can lead to large draw on the electrical system, motor overloading and the potential for damage to occur. By slowly ramping up the voltage, the motor starts off at a much lower speed and gradually builds up over time so that it does not draw too much from the electrical system. Soft start compressors can help lessen wear-and-tear on the motor, allow for longer lifespan of your compressor, and reduce stress on the electrical system. Additionally, they are commonly used in situations where an overload could easily cause permanent damage to other components.

What are the advantages of installing a soft start compressor?

Installing a soft start compressor offers many advantages such as energy savings, extended system life, equipment protection and reduced current demand.

Energy Savings: Soft start compressors reduce the voltage supplied during the starting period, this reduces the inrush current resulting in significant energy savings over time.

Extended System Life: These compressors can help reduce mechanical stress on the motor and other components of the system by gradually increasing voltage over time, which helps preserve their lifespan.

Equipment Protection: Soft start compressors protect delicate circuitry from damage by controlling and managing high inrush currents that are associated with heavy loads. This helps increase safety for the user and makes it easier to install and maintain systems long-term.

Reduced Current Demand: Another advantage of installing a soft start compressor is that it reduces the amount of current needed to initially start up the system, which can be critical when you need to meet certain power requirements or face operational downtime.

What are the potential risks associated with a soft start compressor?

The potential risks associated with a soft start compressor include motor overload, misapplication of components, and damage to the load. Motor overload can occur when the load is too great for the motor to handle and causes the soft starter to trip. Misapplication of components can cause equipment failure due to not having the correct electrical protection equipment or wiring rated for the application. Finally, damage to the load itself can occur when an improper start time is set causing high current inrush and power quality disturbances to sensitive equipment such as computers or control systems. It is important to understand the application and consult a qualified electrician before attempting to install a soft starter.