Soft starters are available for asynchronous motors of different capacities. Many models are specifically aimed at overclocking. However, there are configurations that can provide a smooth engine stop. Starters are most often used on conveyors.
They are also installed on conveyor belts. They are ideal for pumps. The principle of operation of the models is based on a gradual decrease in the current load parameter. In order to understand this issue in more detail, you should consider a simple starter device.
Standard starter circuit
The reversible starting circuit of an induction motor includes a step - down transformer . The relay in this case is installed with a high voltage winding and can cope with a very large overload. If we consider powerful models, then they have rectifiers.
Also, the starting circuit of an asynchronous electric motor involves the use of resistors of a truncated type. In some configurations, transceivers can be found. These devices are designed to reduce the clock frequency of an induction motor. Thus, he is able to serve for many years. Cenotrons in models are often used with stabilizers.
Single phase starters
A soft start of an induction motor due to a single-phase starter occurs due to the supply of voltage to the transformer. Then it is fed to the relay, where the conversion takes place. Most modifications of this type are equipped with expanders. They are used only code, or switched. The outputs are used to connect an induction motor.
Some modifications are sold with regulators. Directly rectifiers are installed operating rooms. The threshold overload parameter of the models does not exceed 40 A. In turn, their power is at the level of 5-10 kW. The parameter of the supply voltage ranges from 100 to 220 V. In terms of protection, single-phase modifications are quite different from each other. Some of them are vulnerable to moisture or dust, and this should be considered before buying.
The device of two-phase models
Two-phase starters should be considered as an example of general production models. This type of electric motors asynchronous (three-phase) specifications have the following: power 5-15 kW, maximum overload 40 A, input voltage rating 220 V. Anchors for versions are used with a primary winding. The models use step-down transformers. It is also important to note that the relays are installed with stabilizers. Modulators for these devices are suitable only orthogonal. Modifications with resistors are very rare.
Three-phase type modifications
Soft start of an induction motor using three-phase starters is fast. If we talk about the characteristics of the models, it is important to note that the threshold load of the device can withstand an average of 60 A. The power of many models exceeds 5 kW. The disadvantage of these devices is considered to be a low threshold minimum temperature. In cold weather, their use is strictly prohibited. Modulators for models are suitable for the orthogonal type.
Expanders are most often found coded. In terms of current throughput, they are quite different. Transceivers, as a rule, are mounted on single-pole starters. Transistors in models are used mainly broadband. In terms of protection, starters differ. Many of them are not afraid of high humidity, but in this case a lot depends on the manufacturer.
Starter for squirrel cage models
With a squirrel cage rotor, asynchronous (three-phase) electric motors have the following characteristics: power from 10 kW, maximum overload is 40 A, input current rating is 220 V. Most starters are equipped with step-down transformers. Some configurations on the market are presented with stabilizers. It is also important to note that models with a power exceeding 12 kW are equipped with special dinistors.
They are ideally suited to stabilize the output voltage. Extenders in all devices use code. However, thyristors are only suitable for the semiconductor type. On average, the minimum temperature of the device is able to keep at 5 degrees. The squirrel-cage induction motor is directly started via the output contacts on the upper part of the housing.
Features of models for starting a high-voltage motor
Soft start of the high-voltage type induction motor is carried out thanks to power transformers. In this control only electromagnetic regulators are used. Directly set kenotrons frequency. Transistors for these models are suitable with high bandwidth. There are two isolators in the devices. To connect high-voltage motors, output contacts are used. Models with dinistors are quite rare.
ABB Starters
Starters in this series are considered very common. In this case, the engine starts due to a phase change. Direct current conversion is carried out thanks to dynistors. By the type of relay, the models are quite different. The power of the models ranges from 4 to 12 kW. In turn, the supply voltage averages 220 V. Distributors are installed only code type.
If we talk about modulators, then on high power models they are orthogonal. It is also important to note that the transceivers in all starters of this series are single-pole. Most often, models can be found on conveyors. There are no stabilizers in the devices. The protection system they have installed IP-62 series, and they are not afraid of high humidity.
Schneider starter
The specified starter has a high input voltage of 200 V. In this case, the engines are started through a power transformer. The relay in this model is used with a primary winding. According to the documentation for the device, the threshold overload parameter is at around 40 A. The resistor in the presented configuration is set-up, and the expander is used code type. Problems with a phase change in this device are quite rare. To convert current, a high-quality modulator is used. Regulator of rotation speed of an asynchronous electric motor of electromagnetic type. The manufacturer provides an expansion dinistor for a model of this type. The zener diode in the device is missing.
Starters for marine vessels
Models for marine vessels are available in different capacities. Email starts engine through a power transformer. If we consider two-phase modifications, they are equipped with rectifiers. Modulators, in turn, are installed both orthogonal and non-condenser type. Resistors, as a rule, are used for tuning. Three-phase starter modifications are equipped with stabilizers. Thyristors are used to change the clock frequency. Kenotrons in this case are installed with high throughput.
Modular models for nuclear facilities
Modular starters have a high output voltage parameter. Email starts motor thanks to step-down transformers. For two-phase models, power analogs are used very rarely. Rectifiers in devices are installed only with relays. Extenders are used as a switched type.
Degree of protection in starters is provided by the IP-67 series. Models are not afraid of increased humidity and dust. Insulators in devices have from three to six units. Power ranges from 4 to 10 kW. The speed controller of the asynchronous electric motor they have an electromagnetic type. It is also important to note that thyristor blocks are installed semiconductor with contacts.
Modular devices for elevator stations
For elevator stations, only two-phase starters are used. Starting an induction motor with a starter in this case is due to the operation of a step-down transformer. These models must keep current overload at 40 A. Extenders for uninterrupted power are most often used code type.
Directly transceivers are used unipolar. Modulators in this case are rarely used. However, modifications are found with regulators. Resistors for models are used both trimmer and pulse type. Modifications with kenotrons are not found on the market. Transistor blocks do an excellent job of overloads. It is also important to note that the models use insulators.
Characteristics of 60 A models
60 A starters are ideal for elevator stations. Soft start of the induction motor in this case is provided by power transformers. Relays for many primary models.
For normal operation of the starter, only orthogonal modulators are used. Directly thyristor blocks can be found in the semiconductor type. They are able to withstand a large load. Power models range from an average of 10 kW.