Electrical Layouts: Sockets, Switches, Lights, Boards, Cables and Circuits

Its three tools

Open **CAD tools** in the tool rail and then **Electrical**. The group has three tools, and each has a command you can type.

**Catalogue** (`ELECTRICAL`): browse the trade's fittings by system, with each one's plan symbol. Picking one arms Place with it.

**Cable** (`CABLE`): draw a run. Click each point; press Enter to finish. The run starts on the trade's usual size, and its size, system and levels are in its panel afterwards.

**Place** (`PLACEELEC`): put down the fitting you picked. Each fitting stands at its usual mounting height, which its panel can change.

A run snaps to the connection points (ports) of fittings, so a pipe or a cable that starts on a fitting is joined to it. A fitting that should be connected and is not is listed in the Issues tab as not connected.

What is in the catalogue

**Power**: double sockets, outdoor and floor sockets, cooker connection units, EV charge points, isolators, junction boxes, appliances (cooker, dishwasher, fridge freezer, washing machine, tumble dryer, microwave, freezer).

**Boards and protection**: consumer units and distribution boards, energy meters, MCBs, RCDs, RCBOs, surge protection, contactors, UPS.

**Lighting**: one gang and two way switches, dimmers, pull cords, scene keypads, ceiling points, downlights, external lights, movement sensors.

**Safety**: smoke, heat and CO alarms, sounders, emergency stops.

**Data, TV and phone**: data outlets and junction boxes, TV outlets, telephone outlets.

**Earthing**: the main earthing terminal, earth electrodes, bonding clamps.

Circuits and the board

**Wiring**: a cable from a fitting to the board wires it to that board. Where a fitting is wired, the wiring decides its circuit.

**Circuit**: every fitting and cable has a Circuit field, the circuit or zone the schedule files it under.

**Ways**: select a consumer unit to list its ways. **Add a way** with its rating and its protection (MCB, RCD, RCBO).

**Switches to lights**: **Controls** (`CONTROLS`): click a switch, then the lights it works.

**Board schedule**: the Schedules tab prints the board's ways, what is on each and their protection, which is where breakers appear, as on any electrical drawing.

The checks

The Issues tab reads the layout as you draw. These are advice, never a refusal:

**Cable size**: a cable too small for its circuit's rating, or long enough to drop too much voltage at the far end (BS 7671 433 and 525).

**Safe zones**: a concealed cable outside the zones a wall cable may run in, within 150 mm of the top or a corner or in line with an accessory (BS 7671 522.6.202).

**Bonding**: no main earthing terminal, or gas and water not bonded to it (BS 7671 411.3.1.2, 542 and 544).

**RCD protection**: a socket circuit with no 30 mA residual current protection (BS 7671 411.3.3).

**Circuits**: lighting or power all on one circuit, a circuit over its rating, a board with no free way, a fitting on a circuit that does not exist.

**US rules**: socket spacing along walls and the protection a circuit needs (NEC 210.52, 210.8, 210.12), and nail plates where a cable passes close to a face (NEC 300.4).

In 3D and on paper

**3D**: runs are built as real cables, pipes and ducts at their levels, and fittings stand at their mounting heights. In 3D you can drag a run's end or its body, and it snaps to corners and to other fittings' ports.

**Through walls**: a run that crosses a wall or a floor cuts its own hole through it, and the hole moves with the run.

**Showing and hiding**: the Layers tab has a switch for each trade, and an X-ray switch that shows the services through the building.

**Sections**: a run cut by a section is drawn as its section, and the ones beyond it along their line.

**Schedules**: the Schedules tab lists runs by size, fittings by kind and boards by circuit. See [Sheets and schedules](/docs/sheets-and-schedules).

Read next

• Plumbing and heating
• Renewables
• Checks and issues
• Sheets and schedules

Frequently asked questions