In modern residential buildings, the ground loop is always carried out separately from "zero" or "phase". This means that 3 drives must go into the flap: red (brown or black), blue (cyan) and yellow-green. But in old buildings, the neutral wire is divided into working and protective, but what is the difference between them and is this system so safe?
What is the difference between "earth" and "zero"
The ground wire that goes into the switchboard must meet several requirements:
- The cross section is not less than 10 mm2.
- From the circuit to the shield and further to consumers, the wire should not have break points - twists, switches, etc. The circuit can only be connected in the shield using a bus.
- According to the PUE, the insulation of the protective conductor should be yellow-green.
"Ground" has a protective function, for example, if a broken phase wire falls onto the housing of a household appliance. And "zero" is used for the full operation of the circuit. You can use "zero" as a protective conductor, but you should be aware of several features of such a system.
Features of using the neutral conductor as "ground"
If the electrical wiring in the apartment is old, there is no ground loop, then do not rush and drive in a metal pin under your balcony. This could draw unnecessary attention from energy auditing companies. You can make a protective circuit, but you need to know the basic rules for such an installation.
- "Zero" into the working and protective circuits must be divided directly in the shield. To do this, you need to make 2 buses connected by a jumper. One is blue with the designation "N", the other is yellow-green with the designation "PE".
- In any device, be it a washing machine or an ordinary socket, the protective "zero" wire must be connected to a separate, specially designed contact.
- The protective "zero" wire cannot be mounted on the grounding contact from the working neutral conductor. This is dangerous for the life and health of consumers, since if the working "zero" is broken, the device case will be under the influence of a dangerous potential.
Only in this way it is possible to mount not only a safe, but also the correct protective circuit in an apartment or a private house.
What to do if there is no protective circuit in the shield
If the ground loop is not provided in the shield, but the necessary knowledge or desire to separate the "zero" no, then you can choose an easier way to protect yourself - install a residual current device (RCD).
The RCD monitors the difference in currents in the network and when the consumer comes into contact with a life-threatening potential, it simply turns off the network. The cost of the device is average, and the installation is not at all difficult, there are many introductory videos on the Internet.
RCD is the most practical and relatively inexpensive solution. In modern panel rooms, this device (or differential switch) is installed without fail.