Switchgear
Switchgear retrofit: modernising during ongoing operation
Spare parts discontinued, power demand increased, safety standards outdated: many switchgear installations have to be modernised while operations continue. Here is how a retrofit succeeds.
TOKSEL Elektrotechnik editorial teamPublished on 4 min read
Switchgear is built for a long service life – many installations in industry and commerce are thirty years old or more. At some point, however, spare parts are no longer available, capacity is no longer sufficient or safety no longer reflects the state of the art. A completely new installation is not always necessary then: with a retrofit, an installation can often be modernised step by step – while operations continue.
When does a retrofit make sense?
- Spare parts have been discontinued: For older circuit breakers and protective devices, spare parts are often no longer available. A failure can then lead to long periods of downtime.
- Power demand has increased: New machines, charging infrastructure or air-conditioning systems push the existing installation to its limits.
- Safety deficiencies: Missing protection against accidental contact, exposed busbars or outdated protection technology increase the risk to staff and equipment.
- Lack of transparency: Without metering, it remains unclear where energy is consumed and where peak loads occur.
- Inspection findings: Periodic inspections or thermography reveal overheating, wear or defects.
Retrofit options at a glance
| Option | Description | Advantage |
|---|---|---|
| Device retrofit | Replacement of individual circuit breakers or protective devices with modern devices using suitable adaptors | minimal intervention, short shutdown times |
| Panel retrofit | Panel-by-panel replacement of individual incoming or outgoing panels | modernisation in stages, predictable budget |
| Extension | New panel or new sub-distribution board next to the existing installation | more capacity without intervening in existing outgoing feeders |
| Replacement with temporary supply | Completely new installation, with supply during the conversion via a temporary feed | latest state of the art with minimal interruption |
The process: thorough preparation is everything
- Survey: Circuit diagrams, labelling and actual wiring are compared – documentation and reality often differ.
- Measurements and thermography: The load, temperature rise and condition of the components show where action is needed.
- Concept: Which option makes sense technically and economically? Short-circuit withstand strength and selectivity are reassessed.
- Shutdown plan: Together with you, we determine when which areas can be shut down – often at weekends, at night or during production breaks.
- Prefabrication: New components and panels are prepared as far as possible to reduce working time on site.
- Conversion: Work is carried out in accordance with the five safety rules (fünf Sicherheitsregeln): disconnect, secure against reconnection, verify that the installation is dead, earth and short-circuit, cover or fence off adjacent live parts.
- Testing and commissioning: testing of the modified parts, functional test, re-energisation.
- Documentation: updated circuit diagrams, equipment labelling and test reports (Prüfprotokolle).
Minimising shutdown times
The most important wish with every retrofit: operations should keep running. There are proven strategies for this:
- temporary supplies or mobile generators for critical loads,
- switching individual outgoing feeders over to adjacent panels or sub-distribution boards,
- prepared cables and connections, so that the actual switchover only takes a short time,
- working in stages, coordinated with shift schedules and production cycles.
The benefits of a retrofit
- Higher availability thanks to modern components with secure spare-parts supply,
- Greater safety thanks to protection against accidental contact and up-to-date protection technology,
- Transparency through metering and communication,
- Cost-effectiveness: Existing enclosures, busbars and cable routes can often continue to be used.
We modernise switchgear and distribution boards in industry and commerce in Cologne, Hürth and the Rhein-Erft district. Find out more under Switchgear construction and Industrial electrical engineering. You will find the basics of planning new installations in our guide Planning a low-voltage main distribution board.
Frequently asked questions
Is a retrofit cheaper than a new installation?
Often yes, because enclosures, busbars and cable routes continue to be used. However, for very old installations or where power demand has risen sharply, a new installation can be more economical. A survey of the existing installation provides clarity here.
Does the installation have to be tested after the retrofit?
Yes. The modified parts are tested and the results documented before the installation goes back into operation.
Can you also work without up-to-date circuit diagrams?
Yes. Missing or outdated documents are the rule rather than the exception with existing installations. As part of the survey, we record the actual wiring and update the documentation.
Related service
Switchgear construction
Low-voltage main distribution boards, sub-distribution boards and meter cabinets – engineered, built and tested to DIN EN 61439.
This article provides a general overview (as of October 2026) and does not replace an assessment or advice in the individual case. The applicable standards, laws and the requirements of your grid operator are decisive.
