Construction Of DOL Starters and Overload Protection

As demand for electricity grows, our systems are heavily taxed to provide stable power to our homes and industries. A variety of equipment helps in ensuring that any glitch in the flow of current does not damage the equipment.

While some opt for a UPS battery to get short-term backup, many opt for a battery backup or generator. In highly specialized environments, some machines are used to protect the electrical fixture when it is connected to the main power source.

A Direct On Line Starter or a DOL starter is one such method that is used to start specific motors, usually, the 3 phase induction motors. These are small rated motors that are typically used in water pumps and fans.

Also known as the ‘across the line starter,’ the device is used to enforce full voltage on the motor terminals. The dol starter ensures that the equipment is not harmed despite being connected to the main source. It gives the machine that it is connected to the protection against overloading or overcurrent. It usually finds use in industrial settings and powers small motors.

How Does It Work?

A DOL starter consists of a protection device, the main contractor, and an overload relay. Together, they are used to start machines that are usually rated below 5HP motors. In this method, the motor stat or windings draw power from the main supply, which is protected by the DOL. This is essential as a connection to the main source can harm the overall circuit of the machine it powers. The damage usually occurs as the initial current is much more than the full current.

A DOL starter is only used if the oncoming current of the motor does not lead to a big drop in voltage in the supply circuit. When the motor is connected to the three-phase supply, the current flows through it is usually up to eight times more than the full current load. When the induction motor is connected to the main supply source, the starting current does not damage the motor unless it is stopped and repeatedly started over a short period of time.

Suppose a large rating induction motor is connected directly to the source. In that case, a heavy starting current can lead to a glitch in the machine. This is why DOL starters are only used for motors that can weather high starting currents without any voltage dips.

What Are The Benefits?

A DOL starter is one of the simplest and most cost-efficient ways to give that initial burst of power. The way the mechanism is designed makes it easy to install. Its simple components ensure that you can find any issues or problems in the system quickly. Besides, its small size makes it easy to place.

Not only does it give the initial current, but it also protects from instances of overcurrent. This happens when there is a faulty current flow in a large amount, resulting from a short circuit. This kind of current can cause a substantial amount of damage to the motor even if the flow is for a short period of time.

Similarly, the DOL starter helps in case the motor draws on more current. This is called an overload situation and can cause the motor windings to melt. This happens when the current flow goes beyond the safe limits and can cause fire hazards.

Where Are They Used?

Small and efficient, a DOL starter finds uses in a variety of industries. It is used to power conveyor belts, fans, water pumps, and compressors. It is also used in motors that have low ratings and where the starting current does not cause voltage dips in line voltage. They also find use in motor windings that are not damaged by starting current.

ADOL starter is a small piece of a machine but packs quite a punch. It is typically used only in industrial settings and is a piece of highly specialized equipment. Suppose you are looking for a DOL starter. In that case, it is advisable that you contact a trained professional who can help you discover the right products by matching them with your needs and installing it safely following industry standards!