Soft Starters
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About soft starters
Soft starters limit the starting current of electrical devices, power supplies and electric motors. This protects mechanical components from excessive torques. In addition, the soft start prevents a strong voltage dip and the triggering of any circuit breaker. Soft starters are used for electrical devices that are held in the hand, such as angle grinders, so that they do not develop jerky movement forces when switched on.
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What was soft starter?
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What are soft starters used for?
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What soft starters are available?
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This is important when selecting soft starters
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Accessories for soft starters
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Note on the installation of soft starters
What was soft starter?
Soft starters are electrical components that are connected upstream of the drive elements. This is usually a combination of different types of switches. Combined in one component to form a soft starter, the switch functions serve to protect, switch and start different applications.
By the way: Soft starters are also referred to as soft starters. The term "soft starter" has become established in English.
In general, the use of soft starters involves the fact that an electric drive does not start immediately at full power when it is switched on. This is to prevent:
- Mechanical components are damaged by an abrupt start.
- That the entire device moves uncontrolled due to the high forces at start-up.
- That circuit breakers in the line network are triggered by the rapidly increasing power consumption.
Some soft starters work with several operating phases:
Soft starters with only one active phase take over the reduction of torque when the electric drive is switched on and switch off as soon as the full motor power can be called up without their intervention.
Soft starters with two operating phases reduce both the torque of the motor and the on-current.
Some soft starters also work during the shutdown process.
The service life of electrical drive elements is increased by connecting a soft starter. The soft starter compensates for fluctuating loads in the power grid, protects against mechanical impacts and thus reduces operating failures. Complex models also provide analyzes of the condition and function of drive elements in industrial plants.
By the way: The counterpart to soft starters are braking devices that accompany the shutdown process. You can find these in our shop also at the soft starters.
What are soft starters used for?
Many soft starters are permanently installed in devices with electric motors such as fans, centrifuges, sawing machines, grinding machines and similar devices.
In vehicles driven by an electric motor, the start phase is also accompanied by a soft starter.
Soft starters are used as starting current limiters for some switched-mode power supplies.
Soft starters are used in industrial applications, for example, for controlling conveyor systems and cranes. In most cases, programmable soft starters are used here, which can be arranged clearly together with the other control technology on a DIN rail.
What soft starters are available?
Soft starters are available in various technical versions. Soft starters can be divided into three large groups on the basis of their applications:
- Current Limiters
- Soft start for power supplies
- Soft start-up for electric asynchronous motors
In the respective functions, there are several technical variants to achieve the goal of slow start-up with limited power and protection against overload.
This is important when selecting soft starters
When selecting soft starters, the first thing that matters is the nominal voltage, nominal current and motor power at which the soft start is to work.
The nominal voltage of the offered soft starters ranges from 24 to 690 volts. Many electric motors operate with a standard mains voltage of 230 to 250 volts, even 400 volts are not uncommon with electronic drive elements. The associated nominal current is 0.2 to 1214 amps.
It is important whether it is AC (AC) or DC (DC). Some changeover soft starters are independant of the conversion of alternating current into direct current, pure direct current soft starters require an upstream frequency converter or modulator.
In addition to voltage and current, the power of the connected electric motor is relevant for the selection of a suitable soft starter. There are motors with less than 1 kilowatt power and those with more than 700 kW. It should also be noted that some electric drives can be supplied with both 230 V and 400 V rated voltage, whereby the respective motor power depends on the voltage applied.
The maximum and minimum operating temperature of a soft starter must not be exceeded or fallen below. They play a role in harsh application environments. Soft starters are often not suitable for minus degrees, i.e. not for outdoor use. Even at high temperatures, the mechanical parts of the soft starter can be damaged, was its reliable function endangered.
If the basic electronic parameters are suitable, you should take a second step to look at the specific functions of the soft starters offered. Here, there are sometimes considerable differences in the switching behavior, since as mentioned above, there are always several technical possibilities for implementing a soft start.
- Simple models are limited in their functional scope to specific application scenarios.
- More expensive versions of the soft starters can be set, i.e. can be programd.
Tip: If you want to integrate a soft starter in a larger switching environment, make sure that it is compatible with the already existing components. Some manufacturers offer product ranges that include soft starters and other intelligent switches.
When installing soft starters, a connection to the electrical cables is usually made using plug connections or terminals. Some soft starters are suitable for quick mounting on a DIN rail.
Accessories for soft starters
Our range includes not only soft starters, but also a wide range of accessories such as:
- Display elements
- Covers
- Fixings
- Covers
- Connection accessories for the electrical cables (terminals, connectors, cables)
- Communication interfaces
- Software licenses
- Tools for installation or disassembly
Tip: In some cases, matching accessories for a product may appear right at the bottom of the product page. A look at the documents for the respective soft starter or accessory provides information on compatibility with other components. If you have any questions, please contact our specialist department.
Note on the installation of soft starters
For safety reasons, the installation of soft starters may only be carried out by qualified personnel with advanced electrical expertise.