How Do Motor Starters Work and Why Do We Use Them?

How Do Motor Starters Work and Why Do We Use Them

What is Motor Starter?

One of the hallmark inventions for motor control applications is the motor starter. A starter, as the name suggests, is an electrical device that regulates the electrical power used to start a motor. These electrical apparatuses are also employed to halt, reverse, and safeguard electric motors. Due to the quantity of energy needed to turn the engine over, the starter motor requires a lot of currents. The starter motor’s high current draw causes the battery voltage to drop when an engine is started momentarily.

A motor starter also offers defense by first regulating your gadget or equipment’s electrical output at its starting point of operation (as you turn it on or as it engages). After then, the starter serves as a fail-safe to keep your system safe.

What are the different types of motor starters?

As the discovery of motors opened a myriad of possibilities in technology and innovations, there has been a remarkable growth of improvements in this technology itself. Along with this comes the development of several types of reliable motor starters. However, there are two basic types of these devices which are as follows:

1.   Manual Starters

Devices that require manual operation are called manual starters. These beginnings don’t need the help of a professional and are really simple and quick to use. A button (or rotary knob) on the starter allows a user to turn the linked equipment on and off.

Mechanical connections built into the buttons cause the contacts to open or close, initiating or stopping the motor.

This type of motor starter has gained a better preference due to the following factors:

  • The manual starter has a low initial cost.
  • A wide variety of enclosures are available for these devices.
  • These starters provide both a safe and cost-effective operation.
  • These devices are excellent for a variety of applications due to their small size.
  • They shield the motor from potential damage by providing overload protection.

2.   Magnetic Motor Starters

This is the additional primary variety of motor starters. It is operated electromagnetically. It indicates that a lower and safer voltage than the motor voltage is often used to start and stop the motor load connected to the motor starter. The magnetic starter features an electrical contactor and overload relay, just like other motor starters, to guard against too much current or overheating.

What is a 3-phase motor starter?

Three-pole, or three-phase, electromagnetic motor-starters are commonly used to operate integral-horsepower three-phase AC (Alternating Current) induction motors. Due to the fact that full line voltage is applied to the appropriate motor leads when the motor-starter solenoid coil is activated, this sort of three-pole motor-starter is frequently referred to as a three-phase across-the-line or full-voltage motor-starter.

Comparatively, with a single-phase motor starter, the power supply is the primary distinction between a single and a three-phase motor. While a single-phase motor requires a starting capacitor, a three-phase motor starts on its own.

What is the function of a motor starter?

To put it simply, by forming or breaking its contacts, the motor starter functions to safely manage the ON/OFF of electrical motors. Smaller motors with manual starters have a hand-operated lever that must be manually moved from the contacts’ OFF position to the ON position.

In addition to starting the motor, a motor starter also works on stopping a motor safely, reversing the direction of the motor, and protecting the motor from low voltage and sudden overcurrent.

These functions are critical for operating a motor making it an integral part of the system. A motor starter plays an important role in starting an induction motor, duly of its low rotor impedance. This rotor impedance greatly depends on the slip of its induction motor, which has a relative speed between the rotor and the stator. This impedance also varies inversely with its slip.

Which is the best motor starter?

Practically, there is no generic motor starter that would be best for everything. Before picking which motor starter is best for you, you should take the load, the type of motor, and the network into account first. You have a long selection to choose from for your choice of motor starters. Motors also come in a variety of sizes and have different levels of capacity and power, and should be suitable with your motor equipment.

What can cause starter failure?

The performance and longevity of your motor starter may depend on its make and model, just like any other device. On the other hand, there are also causes for your starter to fail that lie in your usage, installation, quality of parts, maintenance, and some that are just due to normal wear and tear as they are exposed to temperature changes.

To work on this, here are a few tips that are easy to do to mitigate the failure of your motor starters:

  1. Inspect the connections from time to time. This includes the wirings, cables, mounts, and other factors that contribute to its performance.
  2. Give your equipment proper maintenance. This will keep your device safe from corrosion, dirt, and other damage that may chronically be fatal for your equipment.
  3. Use them properly according to their capacity. Don’t let your devices overwork, as this may cause more wear and tears than usual.
  4. If concerns and issues arise with your motor starters, let the experts do the work. This is for the safety of the device and yours as well. You may have a wide understanding of its mechanisms, but the specialists have more accuracy and precision in their field of expertise.
  5. If you have observed minimal concerns but are still able to get the job through with your device, address the issue immediately. This is to avoid escalation of the concern and to keep these matters from catching you off guard in the future.

How do you test a starter motor?

Motor Starter

For some scenarios where you have to test a starter motor, the very first thing you do is to make sure that your connections from a power source to the engine are reliable and should be functional.

The starter system is easy to use and straightforward, and to test it should be simple. The electrical systems could be checked using a voltmeter, a circuit tester, or a test bulb.

How many years does a starter last?

As a generic rule of thumb, a brand-new starter with no flaws should last for roughly 80,000 starts. Since starters normally last longer in warmer regions, automotive problems are more likely to occur on the worst day of the year, when you need your car the most. While on average, a starting motor typically lasts 100,000 to 150 000 kilometers with cars. The starter motor typically lasts the entire life of the car. However, in some models, it might fail early.

As part of the factors that affect the longevity of a motor starter, the utilization, quality, and maintenance can contribute to how long the device could last.

But here are 5 maintenance tips for your starter motor.

1.   Clean the Connectors

A number of specific connector cables connect the starter motor and battery. The strength of the electric current that is transmitted to the starter relay will be constrained if there are corrosions on the connectors or any other kind of filth or grime. Due to this, the motor won’t be able to provide enough power to fully crank the engine. Additionally, it will damage the motor’s integrity and cause it to wear out too quickly. Therefore, you should always keep the connectors clean.

2.   Tighten the Mounting Bolts

Mounting bolts keep the starting motor in place. The starter’s drive and the flywheel won’t be able to engage in these mounting bolts ever get too slack. When you start the engine and you can hear grinding, that is one sign that something is wrong.

You should routinely check to make sure the starter motor mounting bolts are tightened to avoid this from happening.

3.   Clean the Solenoid

The motor’s starter relay is the solenoid. It will look like a tiny cylindrical thing on top of the motor. The solenoid is connected to the battery by the positive battery line.

It functions as the negative battery terminal’s equivalent. The solenoid also needs to be regularly cleaned and maintained, just like the terminal. If you see any dirt, rust, or debris, sweep it away immediately.

4.   Clean the Terminals

Corrosions on the battery terminals is a common occurrence. When a battery is utilized for an extended period of time, battery acids produce hydrogen gas, which finally makes its way out of the battery.

These gases combine to create the corrosive substances that are normally visible on a battery’s terminals after a few years. The electric current that is transmitted from the battery to the starter motor is weakened when the terminals are covered in this manner. Not only would cleaning the terminals benefit the battery, but it will also benefit the motor.

5.   Inspect the Flywheel

The starter uses the flywheel, a rotating tool, to help crank the engine. A pinion gear is present on the starter’s front side. In order to crank the engine, this gear must mesh with the flywheel.

The flywheel’s teeth and the gear’s teeth must both be in good shape. Your starter motor will not work if these teeth are chipped, damaged, or completely missing. If the flywheel or pinion gear’s teeth are the sources of the issue, replacement is required.

The starter motor may get more quickly worn out if you keep trying to force the two to interact while they are in this state.


A motor starter is a straightforward device that makes it easier to start and stop a motor safely. This simplicity can never equate to the importance it plays in accomplishing the regular tasks we do day by day. As motor starters are an integral part of our daily activity, make sure that you only get reliable versions that you can depend on. Visit to get the best motor starters from Schneider Electric, where your expectations are put to priority.

Article Submitted By Community Writer

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