Replacing a meter cabinet: when it becomes necessary and how the process works

The meter cabinet (Zählerschrank) is the interface between the public power grid and the building's electrical installation. In many older buildings in and around Cologne, it still dates from the 1960s to 1990s. As long as nothing is changed, it may generally continue to be operated. However, at the latest when new large loads are added or a smart metering system (intelligentes Messsystem) is to be installed, replacement often becomes an issue.

Is there an obligation to replace it?

There is no general obligation to replace it. Existing installations enjoy existing-installation protection (Bestandsschutz) as long as they do not pose a hazard. In the following cases, however, replacement is often unavoidable:

• New large loads: Wallboxes, heat pumps, photovoltaic systems or battery storage must be registered with the grid operator (Netzbetreiber). As part of this, it is checked whether the meter board (Zählerplatz) complies with the current technical connection conditions (Technische Anschlussbedingungen).
• Capacity increase or conversion: If the service connection (Hausanschluss) is upgraded or the installation is substantially modified, the current rules apply to the part concerned.
• Smart metering systems: There must be sufficient space for the smart meter gateway and control box (Steuerbox). If there is not, the meter board may need to be adapted.
• Safety defects: Scorch marks, wooden mounting boards, damaged cables or missing protection against accidental contact are reasons to act immediately.

What VDE-AR-N 4100 requires

New meter boards are installed in accordance with the application rule VDE-AR-N 4100 (Technical Connection Rules for Low Voltage, Technische Anschlussregeln Niederspannung) and the supplementary conditions of the respective grid operator. Typical features of modern meter cabinets are:

• standard-compliant meter boards with three-point or plug-in mounting for modern metering devices,
• a space for additional applications (Raum für Zusatzanwendungen) – for example for the smart meter gateway, control box and communications equipment,
• a selective main circuit breaker (selektiver Hauptleitungsschutzschalter) downstream of the meter instead of old screw-in fuses,
• space for surge protection and residual current devices (RCD, FI-Schutzschalter) in the downstream distribution board,
• spare capacity for additional meter boards, for example for a heat pump on its own tariff.

Warning signs: is your meter cabinet outdated?

• Meters and fuses are mounted on a wooden board.
• Downstream of the meter there are screw-in fuses (Schraubsicherungen) instead of a selective main circuit breaker, and there are no RCDs.
• The cabinet is so full that there is no space left for additional devices.
• Covers are missing, cables are exposed, there is a smell of burning or components are discoloured.
• The grid operator has already noted defects in the meter board during a registration.

How the replacement works

1. Survey: We check the service connection, meter board, cables and the planned loads.
2. Planning and quotation: layout of the new meter cabinet, including spare capacity for the coming years.
3. Registration with the grid operator: The conversion is registered and the date agreed. Work on the meter board may only be carried out by the grid operator or by installation companies listed in an installer register (Installateurverzeichnis).
4. Conversion: During the conversion, the building is without power – for a single-family home, usually for a few hours up to one working day.
5. Commissioning: The grid operator or metering point operator (Messstellenbetreiber) installs the meters and seals the meter board.
6. Testing and documentation: measurement in accordance with DIN VDE 0100-600 and handover of the test report (Prüfprotokoll).

What factors determine the costs?

The costs depend heavily on the individual case. As a rough, non-binding guide: for a single-family home, a replacement is often in the region of around €2,000 to €4,000; with several meter boards, new supply cables or extensive additional work, it can also be more. The most important cost factors:

• the number of meter boards and the size of the cabinet,
• the condition and length of the main supply cable and of the cables to the sub-distribution boards,
• the effort required for wall openings as well as plastering and painting work,
• additional components such as surge protection, RCDs or a control box,
• any necessary work by the grid operator on the service connection.

We replace meter cabinets and sub-distribution boards in Cologne, Hürth and the Rhein-Erft district – find out more under Electrical installation. If you are planning the replacement because of a heat pump, our guide Connecting a heat pump electrically will also help.