Protection and faults
What protection belongs in a Spanish electrical panel?
A distribution board coordinates protection against overload and short circuit, indirect contact and overvoltage. There is no universal layout: use, earthing, loads and supply determine the design under ITC-BT-22, 23, 24 and installation-specific rules.
Common faults
Unlabelled circuits, improvised links, too many circuits on one RCD, mixed neutrals, inadequate breaking capacity or a device rated above the cable. A tidy-looking board can still be poorly coordinated.
Homes and other premises
ITC-BT-25 sets minimum dwelling circuits. Commercial, industrial, solar, EV or special-risk installations have their own requirements; copying a domestic board is not a design.
For the next part of the decision, see the guides to RCD tripping and Protective continuity.
RCDs, circuit breakers and the main switch explained
A miniature circuit breaker protects against overload and short circuit within its trip characteristics and breaking capacity. An RCD detects residual current and serves a different protective function; neither replaces the other. The Spanish IGA main circuit breaker protects the internal installation as designed. The meter’s contracted-power control serves a separate supply function.
Overvoltage protection also needs selection for the installation and the source of risk. A single device is not suitable for every home, and transient surges should not be confused with sustained overvoltage. ITC-BT-23 and applicable specific requirements guide the decision alongside the manufacturer’s coordination and connection instructions.
When reviewing a distribution board, the single-line diagram should relate each protective device to its cable and load. Increasing a breaker rating can leave an existing conductor inadequately protected. Clear identification, circuit arrangement and subsequent verification matter as much as the appearance of the board.
Why one standard consumer unit does not fit every premises
A circuit breaker addresses overloads and short circuits, while a residual-current device detects particular leakage currents. Main switching and surge protection serve other purposes. Selection and coordination depend on conductor sizes, earthing arrangement, connected equipment and the rules for the particular use. Adding devices to a board does not improve safety if they are incorrectly selected.
For an old or repeatedly extended board, identify every circuit and check how its cable and protection relate. A repeatedly tripping RCD should not simply be replaced with a less sensitive one. Find the leakage or coordination problem first.
Frequently asked questions
Does an RCD protect against short circuit?
That is not its primary function. Coordinated overcurrent protection is still required.
Is surge protection always mandatory?
The REBT obligation depends on supply and risk under ITC-BT-23; it may also be prudent in further cases.
Regulatory basis and official sources
Always check the current version of the rule and the administrative procedure that applies to the specific case.