Generators are installed to organize backup power in private homes and businesses. This is due to the need, especially in winter, to have an uninterrupted supply of electricity, since most modern heating systems are equipped with electronics, without which they do not function.
Generators are switched by connecting them in parallel to the central power line through a special switch that excludes parallel connection.
Toggle switch: principle of operation
An electrical type device that serves to disconnect an electrical load from one source of energy and connect it to another source is called a toggle switch, or a toggle switch (midpoint switch). Devices come with or without arc extinguishers. In the first case, network switching can occur with a fully connected load. In the second - only when it is turned off.
The circuit breaker is operated manually, that is, if it is necessary to switch the power supply sources, the operator acts on the isolated control lever of the circuit breaker. There are also automatic switching systems.
Toggle switch diagram
The toggle switch consists of a housing, blade-type moving contacts mounted on the shaft, fixed contacts, a control handle, an arc chute (if present) and terminals for connecting to the line. The device has two operating positions (contacts 1 and 2) and one neutral (intermediate), in which no load is connected to any of the lines.
A simple connection scheme for two power sources and one load line looks like this: to contacts 1, for example, a central power supply is connected, to contacts 2 - a diesel or other type of electric generator. The most popular are four-pole and two-pole switches.
Connection of the toggle switch in case of input of three-phase voltage into the building is as follows:
- the switch must be four poles;
- four terminals go to the network input;
- four terminals go to the generator input;
- load is connected to four terminals.
Three of the four terminals go to phases, one goes to zero.
Features
The main characteristics of the toggle switch are:
- Rated current that it can pass. Devices are released on 15.0, 25.0, 32.0, 40.0, 63.0, 80.0, 100.0 and 125.0 A.
- Thermal current that does not destroy elements.
- Admissible mains voltage.
- Short-term impulse voltage that the insulation can withstand.
- Number of poles that a toggle switch can simultaneously switch.
- The wear resistance of electrical contacts is determined by the operating voltage and the magnitude of the transmitted current.
- The wear resistance of mechanical elements is determined by the number of switching cycles.
Modifications of toggle switches
Two-way knife switches are used to work in single-phase circuits. Such switches are equipped with pass-through type capacitors. There are two- and three-module execution. Paired with a toggle switch, a power supply designed for voltages up to 300 volts can work. Install such a toggle switch in electrical panels of various types. When used with a generator, the allowable voltage must not exceed 350 volts. For the load, the average passed current is 30 amperes.
Three-way circuit breakers have a design based on expansion switches. Most often they are used for two-phase circuits and are installed in industrial enterprises. Switches of this type may have interlocks. As a rule, three-way switches have a high sensitivity threshold. The devices are also equipped with a security system.
Circuit breakerflip type
All the toggle switches presented above have one drawback - they require the presence of a person to carry out manipulations with switching circuits. This is inconvenient, especially when the central power supply fails frequently and unpredictably. Therefore, a toggle circuit breaker was developed. More precisely, this is a whole block called automatic reserve transfer (ATS).
AVR is a complex design, but craftsmen assemble such systems from relatively inexpensive relay devices (contactors). For this, models with normally closed and open contacts are used.
When a homemade toggle switch is used, the wiring diagram works according to a certain principle. For example, if there is central supply electricity in the line, then a relay with normally open contacts closes the circuit with the load. The relay with normally closed contacts, where the generator is connected, is open in this case. As soon as the current disappears, the combination is reversed, and the network begins to feed the generator.
Conclusion
The use of toggle switches for switching a generator is a viable solution that allows you to have significant advantages. In addition to facilitating the process of maintenance of an individual power source, this device makes it possible to control the state of the functioning of the network and ensures the safety of the operation of all elements included in the line. To select the optimal switch optionchangeover are primarily guided by the individual characteristics of the electrical network and the devices included in it. Based on this, a toggle switch is selected with characteristics that meet such requirements.
