PV single-line diagrams in Belgium: documentation for electrical contractors

You document a PV system on the single-line diagram as one continuous chain: strings with their MPPT assignment, the inverter with its exact model reference, DC and AC cables, the isolation and protection functions actually present and an unambiguous connection to the board. The situation plan and dossier carry the same references. This guide organises the work from roof survey to handover. It deliberately does not prescribe a universal cable size, circuit breaker and RCD combination – that follows from the actual installation.

Example job: add PV, prepare for a charging point

Our fictional editorial example is a house with main board DB1, two roof slopes and inverter INV1 in the technical room. S1 is on the east slope and S2 on the west. The confirmed manufacturer design assigns S1 to MPPT1 and S2 to MPPT2. A unidirectional charging point EV1 is added later. These names connect the three articles; they are illustrative references, not mandatory designations or an exported PlanElec project.

Power, module counts, protective devices and cable sizes stay open until you have established them for the job. Two strings do not automatically imply two acceptable MPPT assignments: input voltage, current, parallel connections and manufacturer limits are checked separately.

Survey matrix for the contractor

For household PV up to 10 kVA, AREI 7.112.4 lists exactly the data that will later appear in the inspection report: number and rated power of the modules, and number, type, serial number and maximum AC power of the inverters. Keep them properly in the matrix and they are ready on inspection day. Section 7.112.2 adds marking of DC conductors and live AC conductors, warning signs and earthing of the module frames.

Read the diagram and situation plan together

Trace S1 and S2 to the confirmed INV1 inputs, then the AC connection to DB1. The situation plan carries the same references at their actual locations. A roof slope is not an electrical string: multiple strings on one slope remain individually identifiable.

In PlanElec, a PV module symbol on the situation plan represents a complete string and links to exactly one string of the associated inverter. The structured PV side shows single and parallel strings per MPPT, Y-branch or combiner, documented cable segments, entered protection and isolation functions, the AC isolation point and the frame PE to the earthing connection. Missing manufacturer limits and unassigned strings stay visible until you resolve them.

The PV situation plan develops the spatial survey for this job. The PV and charging point guide continues with EV1 as a separate extension. The installation planning guide shows how you get from the electrical model to the diagram.

Record protection from the actual design

An inverter name determines neither trip curve nor residual-current protection. Record the ratings, poles, function and location of the devices actually designed. An integrated function does not appear again as an invented external enclosure. You assess manufacturer requirements and applicable AREI/RGIE rules together; an RCMU line in the datasheet does not do that assessment for you.

For a battery or backup function, also record the genuinely supported operating modes, isolation and supplied sections. A hybrid inverter does not yet prove backup capability. The drawing stays understandable when energy reverses direction.

Equipment checks and the grid procedure

Use the Synergrid C10/26 check to search the exact inverter reference. Compare the result with the current official list and equipment documents. A match proves the device listing, not approval of the completed installation. No match means clarifying the reference – not picking a similarly named model.

The official Synergrid page explains C10/11, C10/26 and their scope. You settle the connection procedure with the distribution operator responsible for the project address. Universal notification deadlines or compensation promises from sample articles do not belong in the job.

Check the handover before export

1. Match S1, S2, INV1 and DB1 across both drawings and their supporting records.
2. Resolve open values against the executed installation instead of inventing typical values.
3. Associate equipment documents, measurements and inspection reports with the correct revision.
4. Update both drawings after any string, inverter or board change.

PlanElec produces the single-line diagram, situation plan and PDF output from the same entered data. For PV, the AREI/RGIE self-check report contains an installation register with inverter identity, power, MPPTs, strings and modules – explicitly a planning register, not an inspection-body report. The roles are clear: the self-check shows you findings within the supported rules, design and measurements happen on site, and the official inspection is done by the approved inspection body.

Primary sources

• FPS Economy: current AREI/RGIE Book 1, the basis for project-specific assessment, in particular Chapter 7.112 (version V06).
• Synergrid: decentralised generating units, for equipment homologation and its relationship to the connection procedure.

Editorial review: 5 October 2026. Links lead to current official publications; check the version applicable to your job and the manufacturer instructions within the project.