For power supply to apartment buildings, a three -phase network with a voltage of 0.4 kV industrial frequency 50 Hz is used. Power supply from the local electrical substation is performed using an underground cable power line. Typically, as a neutral, a composite zero PEN is served, combining zero protective re and zero nourishing n. The separation of their functions is made on the consumer side.
As a rule, there are no general household electrical panels and circuit breakers – the function of protecting the house is performed by equipment in a complete transformer substation. Wiring is carried out sequentially in access electric shoes in most cases through the basement. In each shield, a general entrance circuit breaker and electricity accounting device are installed. Further, the four -wire network is diluted through floor shields. One third of the apartment of the entrance is connected to the first phase, the other to the second, and the third to the last. This is done in order to form a more or less uniform load on each phase. Directly in the floor shield, zero is divided into re and n for each apartment. Thus, a linear single -phase voltage of 220 V is supplied to the apartments. Power of the electrical tanks of the apartment of the apartment is carried out according to a three -wire scheme with a protective zero, and lighting – by two -wire.
In order to exclude unauthorized interference in the access wiring, the first to connect the electric meter to the apartment divert. Behind it is followed by a general circuit breaker for 40 A and RCD protection of electrical appliances from a breakdown of isolation by 63 and at a leakage current of 100 mA. Further, the power is divided into 2-3 groups depending on the availability of an electric stove in the apartment. The first group is intended for lighting, it is installed on it 16 A, the second – for electrical cars, an automatic machine is installed on it 25 A, the third for the electric stove, the machine is installed on it 25 A. On the second and third groups, an RCD with a 10 mA leakage current is mandatory for the second and third groups to protect people from electric shock when directly touching the current parts of electrical appliances or bare wires. A RCD is not placed on the lighting group.
Wiring in apartments is performed in a hidden way in stroobes. In brick houses, drive is performed before the end of finishing work. In panel houses, wall slabs already have strokes and recesses under the electric shows made during their manufacture.
