Electrical installation without grounding: risks and practical solutions

Electrical installation without grounding: dangers and remedies
In a 220 V home, the lack of a grounding system does not guarantee death when touching a metal casing, but it does open the door to shocks that can go unnoticed until the residual current device detects them, or worse, to a discharge that the breaker does not cut off. Spanish regulations, set out in the Low Voltage Electrotechnical Regulations, require a reliable ground connection; without it, protection depends exclusively on the residual current device and on the quality of the insulation.
What solutions exist without redoing the entire installation?
One of the most cited answers is to drive a copper rod into the ground and connect it using a ground cable of adequate cross-section (for example 20 mm²). In a house in Cuenca, a 1 m rod was used, achieving “goodbye shocks and hello residual current device”. The current standard contemplates 1.5 m or 3 m rods, sometimes combined in series to reach the required resistance. Another option is to take advantage of the building's iron mesh or the foundation reinforcement (Ufer), always under the supervision of a certified installer.
The role of the residual current device and the dangers of shortcuts
The residual current device, with a minimum sensitivity of 0.03 mA, cuts the current when it detects a leakage. Some users believe it works the same without grounding, but the reality is that without a low-impedance path the leakage can remain below the tripping threshold. Connecting the ground to the neutral is a prohibited practice: if the connection is reversed, the phase becomes energized and the risk of electrocution skyrockets. Cases of shocks in showers or washing machines frequently appear in accounts from users who tried improvised solutions, such as using water pipes as ground, which is explicitly discouraged.
Costs and economic considerations
Renovating an installation to add grounding can miccionan a special assessment of several thousand euros; one cited case mentions €38,000 for a complete renovation that includes separating grounds and tuning up the panel. The alternative of running the ground from the panel to all circuits is cheaper but still requires civil works and certification.
In short, the absence of a grounding system is not a minor detail, but a vulnerability that can translate into injuries or unexpected costs. What is the best strategy to bring an old home up to code without incurring excessive works?

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