What is a ground loop? To explain it in a simple way, this is a metal structure, a bus and wires, along which the life-threatening potential will go (in the event of a breakdown) to the ground. More details can be found in chapter 1.7 of the PUE. But does grounding ensure safety as this clever book says, and why was this circuit not provided at all in the networks under the Soviet Union?
Ground loop - what should it be?
A real, workable ground loop is:
- 3 metal corners (50x50 mm) at least 2.5 m long, driven into the ground in such a way as to form an equilateral triangle.
- Metal plates connecting the corners and a separate one for laying to the bus inside the shield.
- Grounding bus.
- Grounding wires with yellow-green insulation (according to clause 1.1.29 of Chapter 1.1 of the PUE).
But modern electrics have a lot of nuances and additions, therefore, pin grounding is now widely used - a set that includes a collapsible electrode with a total length of about 6-9 m and special connecting couplings. To mount such a design, you will need a punch and a nozzle suitable for the electrode (can be supplied in the kit).
If the design is similar to that described above, then the ground loop is made correctly, and it can be used for its intended purpose.
Is the installation of the ground loop expensive enough?
The cost is average, and even if you make a structure in the form of a triangle with corners broken into the ground, the price will still come out less than, for example, replacing all the electrical wiring in the apartment. But still.
It is much more expensive not just to make a circuit, but also to lay an additional third wire to all consumers and switching devices, starting with the switchboard. The result is a fairly round sum. And to significantly minimize costs and ensure safety, it is enough to simply mount a high-quality RCD or differential machine in the shield.
The question about cost was raised for a reason, but in order to answer the next one?
Do you need a ground loop at all?
It is enough to imagine a modern apartment with all the sockets in which conclusions are provided for grounding, and even a chandelier, even at the factory equipped with three wires: phase, zero and "Earth".
But how often does the phase wire in the outlet fall off and fall on its case? Not at all. And even master electricians with many years of experience can confirm this - a similar case is one in a hundred thousand.
And why do all the same seasoned craftsmen prefer not to install "land" at all in their home? The answer is banally simple: they perfectly know the specifics of the process and consider it a waste of money.
To mount or not to mount the ground loop is the choice of each owner. But still, this security option was not chosen by the regulatory documentation for nothing, so it's worth considering: maybe you shouldn't skip useful tips?