Soft starters for electric motors belong to the class of combined devices. Their main task is considered to be the distribution of energy. They also help control the power of electric motors. To ensure continuous operation of the motor, they are ideal.
If necessary, they will disconnect the power from the network rather quickly. Today, soft starters are actively used in industry. In particular, models can be found in drilling and milling machines. Such devices are suitable for elevator stations.
Standard starter circuit
The standard circuit of the soft starter motor is a set of contacts. By changing their position, the input voltage parameter changes. Cores in models are often installed pulse type. The electrical coils in the devices are located behind the contacts.
In this case, thermal relays are used with low and high frequency. There should be two conclusions for connecting equipment. Direct movement of the contacts is due to the springs. Control units are diverse. Terminals for models are usually located under the bottom cover. Amplification filters are not installed on all starters.
Single Phase Modifications
A single-phase device that provides electric motor starting (soft starter) is very simple in design. In this case, the coil is selected with the primary winding. Open contacts in models are observed no more than four units. In this case, the core is located under the coil. Directly thermal relay frequency must be kept at least 55 Hz.
There are two conclusions for connecting to the engine in the devices. The springs of the models are used flat. Depending on the control units, starter sizes vary. Some modifications are equipped with sensitivity controls. Their terminals are near the bottom panel. A soft starter of a single - phase electric motor is used often for industrial machines.
The device of two-phase models
A two-phase device that provides electric motor starting (soft starter) is available only with a pulsed core. In this case, thermal relays are installed low-frequency. Direct contacts in models can be up to four units. A trigger is used to change the phase. Many devices also have gain filters. Models are connected through the outputs on the rear panel. Terminals in such devices are located above the top plate. Control units are often available with sensitivity control. You can often meet two-phase models in production. They fit well for milling equipment.
Three-phase type modifications
The soft starters of a three-phase electric motor operate by changing the position of the contacts. In this case, the coils in many models are located behind the cores. A series of open contacts is installed on a special platform. The terminals for three-phase starters can be located above the control unit. However, most often they are located at the rear panel.
Directly thermal relays in such devices are available at 60 Hz. Sensitivity can be adjusted in the equipment due to the lever. The trigger mechanism is installed above the core. Today, three-phase starters often operate with marine engines.
Models for Synchronous Motors
The synchronous device that provides the starting of electric motors (soft starter) is characterized by a reduced frequency. This is achieved through the use of closed cores. Coils for such models must withstand the input voltage at 200 V. Thermal relays are mounted above the upper plate. The make contact system is located on both sides of the core.
To increase the sensitivity of the device, a special regulator is used. Terminals for models can be mounted at the top and back of the panel. Amplification filters are rarely used. In this case, the triggers are set often.
Induction motor starters
To date, an asynchronous device that provides electric motor start-up (soft starter) is produced with various configurations. Inductors in models are installed at 220 and 300 V. .. In this case, the cores are often used open type. On average, their bandwidth parameter reaches 5 megapixels. However, pulse type cores are also on the market. They differ from other models in increased sensitivity. At the same time, they wear out extremely slowly, and are able to work for a long time. Open contacts in the devices are located at the top of the plate.
Thermal relays are installed exclusively low-frequency type. They must be able to withstand the output voltage at a minimum of 230 V. The connection of many models is through the terminals. To change the position of the lower contacts, springs are used. Often they are often installed not of large diameter. The control units in all devices are equipped with locks. Sensitivity adjusters are also present in all configurations. By the type of triggers, the models are quite different. If we consider the soft starters of induction motors with 220 V coils , then they are most often of the wave type. However, phase analogs are also on the market.
Special attention in such devices deserves a trigger. As a rule, it consists of sets of conductors. Nowadays, the most common are modifications to four contacts. If we consider models with inductors at 300 V, then in this case the triggers are always used phase type.
Features of high-voltage engine starting models
High-voltage starters are widely used in nuclear energy. Coils for such devices are often set to 300 V. The bandwidth parameter fluctuates around 5 megapixels. Directly contacts are both mobile and non-mobile. Cores are installed pulsed as well as capacitor type. They differ from each other in terms of sensitivity. Today, pulse modifications are considered more reliable.
Thermal relays for appliances are only low-frequency. The operating current in the system reaches 5 A. The plate springs are used to adjust the plates. The control units in the starters are available with and without interlocks. Triggers are often mounted on three conductors. Amplification filters in this case are used very rarely.
The type of triggers deserves special attention in devices. If we consider low-frequency devices, then they are selected only of the wave type. With a decrease in the sensitivity of the device, they cope well. A soft-start device for the high-voltage electric motor is connected via terminal closure. Often they are located on the top cover.
ABB Series Model
The ABB soft starter is characterized by phase triggers. Their advantage over wave modifications lies in the ability to quickly cope with electromagnetic interference. Thus, the engine works more stably, and the speed always maintains at the right level. Amplification filters can only be found in low-voltage devices. The plates on the models are fixed on flat springs. Triggers are installed on the control units. Directly the frequency the user is able to control with the lever.
Inductors in such devices of the ABB series are installed at 200 V. The contacts are located on both sides of the plate. Cores are often installed closed. As a result, their wear is extremely small. Thermal relays can be found both stepped and reference type. There are only two conclusions in the devices. Models of this type can only be used in networks with alternating current. In this case, the output voltage parameter should not exceed 220 V.
Schneider starter
The Schneider soft starter is equipped with a 230 V coil. It can withstand loads of 6 A maximum. In this case, the open contact network is located near the thermal relay. The core of the model is set to pulse type. Its bandwidth parameter is a maximum of 6 megapixels. A thermal relay is installed immediately below the plate. The outputs of the model are available with terminals. Movable contacts in the system are mounted on flat springs. The control unit is provided in the device standard.
The lock is in it. The trigger mechanism is installed on four contacts. A gain filter is not provided in the starter. However, there is a lever to adjust the frequency. The trigger is set to phase type. It is mounted in the device above the bottom plate, next to the movable contacts. Suitable device for controlling synchronous motors.
Devices for marine vessels
Models for marine vessels include open cores. Directly, the coils are installed at 300 V .. Overload device for a soft start of the electric motor must withstand a maximum of 6 A .. The bandwidth parameter of such modifications reaches 7 megapixels. To connect models, special conclusions are used. Often they are mounted above the core at the plate.
Control units for protection can be equipped with blockers. Triggers on the device are quite different. If we consider low-frequency models, then they are often installed on four conductors. In this case, the terminals should be near the core. Sensitivity for models of this type is not adjustable. Amplification filters are present only in starters with wave triggers. Movable plates in devices are installed near thermal relays.
Modular models for nuclear facilities
Devices for nuclear power are equipped with reliable protection systems. There are about five plates with contacts at the devices. Coils in devices are installed the most diverse. In some cases, they are mounted on the rear panels. There are two outputs for connecting devices. Thermal relays are often used in the low-frequency type. In this case, only pulse cores are suitable.