# Domain Context: Distribution Board Circuit List

## Purpose

In electrical building design, especially during detailed design / execution planning, a circuit list is created for each distribution board.

The circuit list documents all consumers, devices and circuits supplied by or installed in a specific distribution board. It supports:

- construction of the distribution board by the electrical contractor
- execution planning and technical coordination
- quantity takeoff for tendering and cost estimation
- determination of required protective devices, terminals, modular DIN rail devices and related components
- structured documentation of the internal electrical path inside the distribution board

Although the term "circuit list" is used, the list does not only contain final outgoing circuits. It may also contain or later support devices and functional components such as:

- main switches
- surge protection devices
- KNX devices
- control devices
- modular DIN rail devices
- reserve circuits
- other distribution board components

## Important Domain Rule

A circuit list entry is not always just a single independent circuit.

A circuit can contain one or more device rows.

If a circuit contains one device, it can be displayed as one compact row.

If a circuit contains multiple devices, the UI displays:

- one circuit summary row
- one or more indented device rows below it

Circuit-level data such as protection device, cable type and cable length belongs to the circuit, not to each individual device.