# Future Sizing and Calculation Requirements

These requirements are not part of the first implementation, but the structure should support them.

## Goal

The app should later support rule-based protection and cable sizing.

Future suggestions or checks may include:

- protection device type
- rated current
- tripping characteristic
- cable type
- number of cores
- cable cross-section
- minimum cable cross-section based on current
- maximum permissible cable length based on voltage drop
- warning messages if cable length, cross-section or protection device do not match

Users must remain able to manually override suggestions.

## Initial Design Rule Examples

These are common planning defaults, not a replacement for full norm-compliant calculation.

### Lighting Circuits

Lighting circuits in section `-1Fx` usually use:

- protection rated current: 10 A
- cable cross-section: 1.5 mm²

Typical cable type:

- non-DALI lighting: 3x1.5 mm²
- DALI-capable lighting: 5x1.5 mm²

The app should later suggest the cable type based on whether the connected luminaires require DALI or additional control cores.

### Standard Single-Phase Circuits

Standard single-phase circuits in section `-2Fx` usually use:

- protection rated current: 16 A
- cable cross-section: 2.5 mm²

This applies to many typical socket circuits and standard single-phase loads.

### Special Loads and Long Cable Runs

For non-standard loads or long cable runs, voltage drop becomes more important.

Examples:

- instantaneous water heaters
- socket combinations with higher connected load
- outdoor circuits with long cable routes
- lighting circuits with looped-through luminaires and cable lengths of 80 to 100 m

The app should later show warnings or require review if voltage drop becomes critical.

## Future Field: Control Requirement

To support cable suggestions for lighting circuits, devices or circuits may later include a control requirement.

Example values:

- none
- DALI
- KNX
- switched only
- dimmable
- other

For lighting circuits:

- no additional control cores: suggest 3x1.5 mm²
- DALI required: suggest 5x1.5 mm²

This must be configurable and manually overridable.

## Future Voltage Drop Check

A future voltage drop check may use:

- phase type
- voltage
- circuit total power
- apparent power or current
- cable material
- cable cross-section
- cable length
- protection rated current
- allowed voltage drop

The result should be shown as a warning or status indicator, not as an automatic forced change.