Consumer unit labels: identify every circuit and print labels at the right size

Why label every circuit in the consumer unit?

Labelling is first a safety matter. Before replacing a light fitting or a socket, you need to isolate the right circuit without guesswork and without cutting power to the whole home. A readable label also avoids resetting a breaker blindly after a fault.

In the UK, BS 7671 Regulation 514.8.1 requires protective devices such as fuses, circuit-breakers and RCDs to be arranged or identified so that the circuit they protect can be identified, and Regulation 514.9.1 calls for a legible diagram, chart or table describing the circuits (IET, Provision of information within BS 7671). In France, NF C 15-100 likewise requires each circuit to be labelled with the rooms and function it serves. Consistent labelling also helps the electrician during fault finding, extensions or the sale of the property.

• Isolate only the circuit you are working on.
• Find the source of a trip quickly.
• See the spare ways available for a new circuit.
• Hand over an installation future occupants can understand.

What should a consumer unit label show?

A good label uses few words but is enough to identify the circuit without another document. Ideally it pairs a short reference that stays stable over time with a description occupants understand.

The reference — for example PC01 for a socket circuit, ECL02 for lighting or PC-SPE03 for a dedicated circuit — links the label to the diagram and the circuit schedule. The description names the rooms served or the appliance supplied.

• The circuit reference, identical to the diagram and schedule.
• The description: rooms served or appliance (oven, washing machine, EV charger…).
• The breaker rating and conductor size.
• At the start of each row, the 30 mA RCD with its type and rating.
• Blank spaces for spare ways, to fill in when a circuit is added.

Height and width: measure your label holders

Every modular device takes a whole number of modules. The standard module width is 17.5 mm, but many enclosures and busbars use an 18 mm pitch. Across a 13-module row, that half-millimetre adds up to more than 6 mm: a strip printed at the wrong pitch no longer lines up with the breakers.

Label holder height depends on the manufacturer and varies between enclosures. Measure it on the cover, or on the original label supplied with the enclosure, rather than assuming a standard value.

• Measure several breakers side by side, then divide by their number of modules.
• Measure the usable height inside the label holder window.
• Note the number of modules per row: usually 13 or 18.
• Spot devices wider than one module: RCDs, four-pole or three-phase devices.

Generate labels from your floor plan with Planelico

Once circuits and the panel have been generated from your plan, Planelico already knows every row, every RCD and the exact position of every breaker. The labels reuse this data, so they stay consistent with the circuit schedule and the diagram.

In the electrical panel window, the “Export labels” button opens the settings: label holder height from 10 to 50 mm, module width of 17.5 or 18 mm, and whether to show plan symbols and descriptions. A live preview shows the result before export. This feature is included in the Pro plan.

Each label can show the symbol of the most common item on the circuit: a socket, a light point, a washing machine or an EV charger. If you prefer cleaner labels, hide the symbols or descriptions and the remaining text grows to use the space.

Planelico’s panel generator currently follows the French NF C 15-100 rules; check references, ratings and cable sizes against the regulations that apply to your project.

Print, cut and fit the labels

The document is landscape A4, with one strip per row of the panel. For the labels to line up with the breakers, print at actual size: 100%, without the printer’s “fit to page” option. A 100 mm ruler at the top of the page lets you check the scale with a tape measure.

Cut each strip along the crop marks and slide it into the holder of the matching row. An 18-module row wider than the sheet is split across two strips, never cutting a device in half.

• Check the 100 mm ruler before cutting.
• Use thick or adhesive paper for a longer-lasting result.
• Start with the RCD on the left of each row.
• Keep the PDF to reprint a strip after a change.

The circuit directory for the enclosure door

Labels have little room, so long descriptions are shortened. The document therefore ends with a complete circuit directory, to stick inside the enclosure door or keep with the property documents.

For each circuit it lists the reference, full description, protection, associated RCD and areas served, including the floor. It is the first document an occupant or an electrician will check during any work.

Keep labels faithful to the installation as built

Generated labels reflect the panel proposed from the plan. If the electrician groups circuits differently on site, or a circuit is added later, update the project and export the labels again: inaccurate labelling is more misleading than none.

The generated panel remains a pre-sizing aid. The final layout, protective devices and their labelling must be approved by a qualified professional when the work is carried out.

Quick method with Planelico

1. 1

   Generate the panel from the plan

   Place equipment in the rooms, then generate circuits and the panel.

2. 2

   Measure the enclosure

   Record the module width (17.5 or 18 mm) and the label holder height.

3. 3

   Open “Export labels”

   In the electrical panel window, set the height, width and symbol display.

4. 4

   Print at actual size

   Print at 100%, then check the scale with the 100 mm ruler.

5. 5

   Cut and fit

   Cut the strips along the crop marks and slide them into each row.

6. 6

   Stick the directory

   Place the circuit directory inside the enclosure door.

Frequently asked questions

Sources

• IET Wiring Matters (via Voltimum) — Provision of information within BS 7671
• Schneider Electric — NF C 15-100 requirements for the electrical panel (in French)