Installation of Swiss Low-Voltage Distribution Boxes

Installation of a low-voltage power distribution box in Switzerland must comply with the Federal Ordinance on Low-Voltage Installations (NIV/OIBT), be performed by licensed electricians, and undergo mandatory inspection for safety certification.

Regulatory Requirements

In Switzerland, all low-voltage electrical installations, including distribution boxes, are governed by the Federal Ordinance on Low-Voltage Installations (SR 734.27), which sets the legal framework for installation, modification, maintenance, and inspection of systems operating up to 1,000 V AC or 1,500 V DC . Compliance with recognized technical regulations is mandatory, and only licensed electrical installation companies are authorized to perform work on these systems .

Installation Process

1. Planning and Design: Use approved technical standards and planning tools, such as SIMARIS or BIM software, to design the distribution system for safety, efficiency, and load management . Ensure the box is suitable for the building's electrical load and automation requirements.
2. Licensed Installation: Only a licensed electrician may install the distribution box and assume responsibility for the consumer unit fuse and connections . The installation must follow Swiss working standards (WV-CH) and the manufacturer's instructions.
3. Connection and Safety Measures: Proper grounding, circuit protection, and labeling are essential. The box should include protective devices such as circuit breakers and residual current devices (RCDs) according to the load and building type .

Inspection and Certification

After installation, a final inspection is required to ensure compliance with safety standards. The inspection is performed by an independent inspection company or accredited body, which checks for defects and issues a proof of safety (SiNa) . The original SiNa remains with the owner, while a copy is sent to the local distribution system operator (DSO). For installations in offices, shops, or workshops, an additional acceptance inspection within six months may be required.

Periodic Inspections

Electrical installations must undergo periodic inspections at intervals determined by the type of building and risk level, ranging from 1 to 20 years . The owner is responsible for scheduling and financing these inspections. The DSO will notify the owner in advance, typically providing six months to complete the inspection.

Key Recommendations

• Always hire a licensed electrical installation company for installation and modifications.
• Ensure the distribution box and all components comply with Swiss and IEC standards.
• Maintain proper documentation, including the proof of safety (SiNa), for legal and insurance purposes.
• Schedule and complete periodic inspections to maintain compliance and safety. Following these steps ensures that your low-voltage power distribution box is installed safely, legally, and efficiently in Switzerland.