Frequent cases of power failure, as well as the need to connect consumers to 380 Volts force residents of the private sector to use a three-phase generator. In this case, you need to figure out how to connect the electric generator to the networks of a country house, using the equipment installed in them. To solve the problem, you should familiarize yourself with several inclusion methods practiced by residents of private households.
Varieties of generators
By the type of fuel used in the unit, all known generating devices can be:
- gasoline;
- diesel;
- gas or wood burning units.
The first two options attract the attention of users who take as a basis a finished engine running on gasoline or diesel fuel.
Devices on gas and wood are less effective when used in the household and are rarely used.
According to their purpose, well-known samples of three-phase current generators are divided into main and backup units. The question of how to include in the household network applies to both models.
Device and basic parameters of generation
A three-phase generator is a device operating on the principle of converting the mechanical energy of a rotating shaft into electricity. In addition to the movable part associated with the drive, it includes three coils drawn from many windings and placed on the stator core. In brushless generators, when the rotor rotates in the coils, EMFs are induced, which in their parameters correspond to the standards of a 3-phase mains supply. This means the following:
- the resulting voltages are in the form of a sinusoid;
- the amplitude of each of the 3 phases is equal to 220 volts;
- the voltage between them is 380 volts;
- frequency of generated oscillations - 50 Hertz.
A design feature of such aggregates is a phase shift of 120 degrees.
From the stator coils, an alternating voltage is supplied to the serviced line, providing it with the necessary power supply of 380 volts.
How to choose a three-phase generator
When choosing branded units will have to consider the following characteristics:
- type of energy carrier;
- device power output;
- the presence of additional features.
The type of fuel is selected taking into account specific operating conditions (ease of storage of fuel in a residential building). The output power of the purchased unit is selected taking into account the expected load, this indicator varies from 5 to 6 kW for each single-phase branch. When introducing additional functionality, special attention is paid to the following features:
- adjustment of parameters of 3-phase voltage (its shape, in particular);
- the ability to connect additional lines (load capacity);
- the presence of an electromagnetic relay regulator.
It is important to make sure that the selected model has indicators that allow you to visually control the level of each voltage.
Wiring diagrams
Having dealt with auxiliary questions, they go directly to connecting the generator to the serviced line.
Connection via an additional switchgear
The circuit of connecting the machines from the line and the generator is practically the same, which allows you to not change anything in the current three-phase power supply network.This approach to the inclusion of a private house in the network is the most reliable and guarantees the successful operation of the equipment connected to it. To implement it, you will need to do the following operations:
- Disconnect the 380 Volt input circuit breaker by disconnecting the home network.
- Install a new 4-pole circuit breaker in the shield, the output terminals of which are connected by segments of conductors with the input contacts of all linear devices.
- The cable from the generator output with 4 cores (3 phases and zero) is connected to a new machine and each of them is connected to the corresponding terminal.
If an RCD is installed further according to the circuit, when conducting the switching, the wiring of the conductors connected to it (each of the 3 phases and zero) is taken into account.
Connection through a switch
The cross over switch is the same switch, but having three positions. When it is used, the buses from the generator device are connected to one set of poles, and the supply wires from the high-voltage line to another. The central contact set of the switch, the conductors from which go directly to the load, is alternately thrown to the input side from the explosive or to the generator wiring. In the middle position of the switch, the entire home network is completely de-energized.
Auto Switch Scheme
It is possible to get rid of the need to manually select the power source by using the automatic switching circuit of the load connected to it. It consists of at least a control module and two starters (contactors) with cross-connection. The first of these nodes, made on the basis of a microprocessor, semiconductor transistors or analog microcircuits, performs the following functions:
- recognition of the situation with the loss of electricity in the main supply line;
- subsequent disconnection of the consumer from it;
- switching it to a tap from a 3-phase generator.
In the process of operation of a module that recognizes the loss of centralized power supply, a rectangular pulse is generated that enters the actuator (contactor coil). This leads to automatic switching of the switch to the mode of operation from an autonomous generator. When the main power is restored, another control pulse transfers the system to its original position.
Through a power outlet
To connect the generator to the network at home through an outlet, you will need to carefully read the features of this method. Despite its simplicity and ease of connection, this option has many negative sides, expressed in the following:
- the need to constantly ensure that the input circuit breaker is turned off;
- the need to purchase a special 4-pole outlet, designed for high currents;
- restrictions on the load connected to the generator.
The way to connect through the outlet is the worst of all possible. Its use is unacceptable under any conditions.
