Why grounding doesn't just work as long as it's connected - but as long as the connection remains
Bad grounding does not primarily come from a bar or rod.
The most common problems are in the connections — they oxidize, loosen, or are incorrectly made.
However, the same errors are repeated from construction to construction, causing later measurement, reliability and safety problems.
Below are five common mistakes that you can see over and over again in real life.
1. All connections are made with bolts only
The bolt connection is suitable for interfaces inside the shield, not in the ground.
In the soil, interfaces oxidize and the resistance becomes unstable and increases over the years.
Grounding connections in the soil must be:
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welded,
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pressed,
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or performed by thermal reaction (exothermic weld).
2. PE and PEN are connected in random order
This is one of the most critical errors in building electrical panels.
PE must be separate and of primary priority.
PEN is brought to the shield, disconnected, and PE continues uninterrupted to all consumers.
Incorrect sequence (PEN → equipment PE → ground → shield PE → forward) can energize the metal housings of the equipment if the PEN is interrupted.
3. The ground terminal is used as a multiple distribution point
PE busbars are often used as distribution points, not as through connections.
If one screw or section loses contact, several branches will be left without ground.
Grounding must be a continuous connection , not a “star” system with random branches.
4. The ring ground is not closed
The tape is installed around the building, but one connection point is left unmade.
The result is a half-ring – it does not provide stability or reduce seasonal resistance fluctuations.
A proper ring grounding must be a mechanically and electrically closed loop .
5. Potential equalization is done partially or forgotten altogether
It is the equalization of potentials that helps prevent dangerous touch voltages.
Often left unconnected:
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metal water pipes,
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ventilation and sewage metal parts,
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metal grids for underfloor heating,
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external metal structures.
Their potential may differ from the PE level by tens of volts in a safety situation.
