Electrical calculations
Installed power and maximum admissible power explained
Installed power is the sum of the loads’ nominal ratings; design demand applies the relevant utilisation and diversity criteria. Maximum admissible power is the capacity supported by the documented installation. Contracted power is a commercial limit and does not itself change the wiring’s capacity.
Four power figures that should not be confused
- Installed load is not constant simultaneous demand.
- Design applies diversity and use-specific rules.
- Maximum admissible power follows the most limiting section.
- A contract increase may require work and updated documents.
Where the values appear
The project or MTD supports load assumptions and calculations; the CIE records the completed installation. Distributor supply data does not replace the owner's technical records.
Why increases fail
Service cable, board, main protection or final circuits may limit capacity. Documents may be missing or alterations unregistered. Diagnose before applying for an increase.
For the next part of the decision, see the guides to Power and current and Electrical certificate.
Installed load, design demand and contracted power
A home’s appliance ratings may add up to more than its contracted power because the appliances do not all operate together. Their nominal ratings describe installed load; design demand applies the relevant utilisation and diversity criteria. Confusing these quantities can lead to undersizing or paying for more contracted power than necessary.
Maximum admissible power must relate to the certified installation and its actual limits. For reference, 25 A at 230 V single phase corresponds to 5.75 kW at unity power factor. That calculation does not prove that any installation with a 25 A breaker is suitable: cables, joints, protective devices and records need checking.
Before increasing contracted power in Menorca, review the CIE and ask the network operator what the change requires. A paperwork limitation may call for updated records; a technical limitation requires electrical work. Changing the contract alone does not upgrade an undersized feeder or an inadequately protected board.
An example before requesting higher contracted power
A business can have equipment whose nameplate ratings add up to more than its contracted power because not all loads run at once. That sum is different from diversified design demand and documented maximum admissible power. If new machinery is added, compare likely demand with the supply cable, distribution board, protective devices and CIE. Changing a contract figure does not strengthen the wiring.
Ask which number represents connected load, which is design demand and which is maximum admissible power. This avoids commissioning an unnecessary upgrade or, conversely, changing the electricity contract without checking an installation that can no longer support the intended loads.
Frequently asked questions
Are installed and contracted power the same?
No. One is technical and the other commercial; simultaneous demand can be below total connected load.
Regulatory basis and official sources
Always check the current version of the rule and the administrative procedure that applies to the specific case.