What does Siemens Energy buying Camlin mean for owners of Camlin monitors?
On 2 June 2026 Siemens Energy agreed to buy Camlin Group, the maker of the TOTUS transformer monitor. Camlin will be wholly owned by Siemens Energy but managed independently, and closing is expected before the end of 2026. Nothing changes on day one. What changes is who decides the roadmap, so owners should secure their data, support terms and interpretation methods now.
If you bought an online monitor in the last few years, you chose a sensor, a software platform and a company. The sensor is bolted to your transformer for the next fifteen years or more. The company behind it can change in a single press release.
That is what happened to Camlin customers in June. It is also what happened, earlier this year, to customers of Megger. Transformer monitoring and testing are moving into fewer and larger groups, and an asset owner who depends on one of them should plan for it the way they plan for any other supply risk: calmly, and before it matters.
On this page (7 sections)
What exactly was announced?
The announcement came from Siemens Energy and quotes both a member of its executive board and Camlin’s chief executive. It describes an agreement, not a completed deal.
| Item | What the announcement says |
|---|---|
| Date | 2 June 2026 |
| Buyer | Siemens Energy |
| Company acquired | Camlin Group, Lisburn, Northern Ireland: grid monitoring, analytics and asset digitalisation |
| Size | About 650 employees, revenue of over Ā£90 million |
| Governance after closing | Wholly owned by Siemens Energy, managed independently, current leadership team stays |
| For customers | Business operations continue as usual, according to Camlin’s chief executive |
| Closing | Expected before the end of 2026, subject to regulatory approvals |
| Price | Not disclosed |
Camlin’s best-known transformer product is TOTUS, a monitor built around dissolved gas analysis of up to nine gases plus moisture, with partial discharge, bushing and through-fault modules as options. Its installed base is the reason this deal matters to asset owners, and the reason the commitment to independent management is the line customers will read twice.
One detail is often lost in coverage. Siemens Energy has been a separately listed company since September 2020, when it was spun off from Siemens AG. Reinhausen’s TESSA APM suite is offered through Siemens Xcelerator, a partner ecosystem run by Siemens AG’s Smart Infrastructure business. These are two different companies with two different strategies, and the Camlin deal should not be read as one Siemens assembling the whole monitoring stack.
Is this part of a wider pattern?
Yes. In 2026 alone, two of the best-known independent names in transformer monitoring and testing agreed to join larger groups. Looking back a few years, the same movement shows in how the main suppliers are owned.
| Supplier | What changed | When | Status |
|---|---|---|---|
| Camlin (TOTUS) | Agreed acquisition by Siemens Energy | June 2026 | Closing expected before the end of 2026 |
| Megger | Acquired by ESCO Technologies from TBG AG for about $2.35 billion, to be combined with Doble, already part of ESCO | Announced April 2026 | Completed 1 October 2026 |
| Qualitrol (with Serveron) | Moved with Ralliant when Fortive spun off its Precision Technologies segment | June 2025 | Completed 28 June 2025 |
| Hitachi Energy (former ABB Power Grids) | Joint venture formed in 2020; ABB sold its remaining stake to Hitachi | 2020 to 2022 | Completed 28 December 2022 |
| Reinhausen (TESSA APM) | Certified partner in Siemens Xcelerator, a distribution partnership, not an ownership change | April 2024 | Partnership |
The Megger deal is the largest of the year. ESCO expects Megger to bring about $590 million of revenue in 2026, and Doble describes the combination as joining Megger’s portable test equipment with its own substation testing, condition monitoring, diagnostics and laboratory analytics. For a utility that tests with Megger instruments and monitors with Doble systems, two suppliers are becoming one.
None of this says the products will get worse. Large groups can fund research, service networks and cybersecurity work that smaller companies struggle to pay for. The point is narrower: when your monitoring supplier is acquired, the decisions about your installed base move to people you have never met, on a timetable you do not control.
What changes for a utility that owns a monitoring system?
In the short term, very little. Contracts stay valid, field service continues and both announcements stress continuity. Integration choices are usually made after closing and play out over years, not weeks.
Over a longer horizon, three things can move. Product lines that overlap with the buyer’s own portfolio may be merged, renamed or retired. Software platforms tend to converge on one, which can mean a migration with new licence terms and a new hosting model. And the interpretation layer, the rules and thresholds that turn gas readings into an alarm, can change with the platform, sometimes without the change being obvious in the alarm itself.
The third point deserves the most attention. A monitor that raised an alert at one threshold under the old software and at a different one under the new software will give you a different alarm history from the same oil. Our article on online DGA monitors that disagree with the laboratory shows how much depends on knowing which method produced a number.
Which questions should you ask your supplier now?
These questions are worth asking any monitoring supplier, acquired or not. A change of ownership is simply a good moment to get the answers in writing.
| Question | Why it matters | A good answer looks like |
|---|---|---|
| Can we export all raw readings with timestamps? | Your history is the most valuable output of the monitor, and it must survive any platform change | A documented export of every gas value, unit and sampling time, in an open format, at no extra cost |
| How long will firmware, spare parts and calibration be supported for our installed units? | The sensor outlives most software roadmaps | A stated support horizon per model, written into the service agreement |
| Which method and edition produce each alarm? | Thresholds can change with a software release | The standard and edition named for each rule, for example IEEE C57.104-2019 or IEC 60599:2022, and a change log |
| Will licence terms or hosting change after closing? | A forced migration can alter cost, data location and access | Current terms honoured to the end of the contract, with notice before any change |
| Will the platform keep reading other suppliers’ devices and laboratory data? | Most fleets mix monitors from several makers with laboratory reports | A commitment to keep existing third-party integrations working |
If you are choosing a new system rather than reviewing an existing one, our buyer’s checklist for transformer condition monitoring software covers the same ground in more detail.
Why keep the diagnosis independent of the hardware?
Because the two have different lifetimes. A dissolved gas monitor is a measuring instrument; the diagnosis is a reading of what it measures, against published methods. The Duval triangles, the gas ratios of IEC 60599 and the status levels of IEEE C57.104 do not belong to any supplier. If your interpretation can be repeated from the raw values with a named method, it survives a change of supplier, a change of platform and a change of owner.
The same is true of laboratory results, which most fleets still depend on for the majority of their units. Keeping monitor data and laboratory data readable side by side, with the method written next to every conclusion, is what lets you compare a unit’s history across ten years and three software versions. It is also what lets you hand the file to an independent reviewer when a decision is contested.
With large power transformers taking up to four years to replace, the continuity of your condition history is not an IT detail. It is part of how you decide which units keep running.
What can be done this quarter?
- List every monitor in the fleet with its maker, model, software platform and the date of the last data export.
- Export the full raw history from each platform and store it in a format your team can open without the supplier’s software.
- Ask your supplier, in writing, the five questions above, and file the answers with the service contract.
- For each alarm rule, record the method and edition it uses, so a future change can be spotted.
- Check that laboratory reports and monitor readings for the same unit can be read on the same timeline.
An acquisition is a good reason to look at your contracts. It is a better reason to make sure your data does not depend on any of them.
Sources
- Siemens Energy, Siemens Energy expands capabilities with Camlin Group acquisition, 2 June 2026.
- Camlin Energy, TOTUS G9 transformer monitor, product page.
- Deutsche Bƶrse, Siemens Energy AG new in Prime Standard on the Frankfurt Stock Exchange, 28 September 2020.
- Siemens Smart Infrastructure, Siemens Xcelerator partner ecosystem expanded with asset monitoring from Maschinenfabrik Reinhausen, 24 April 2024.
- ESCO Technologies, ESCO announces agreement to acquire Megger Group Limited, 15 April 2026 (SEC filing, exhibit 99.1).
- Doble Engineering, Doble Engineering and Megger unite to shape the future of electrical asset management, 16 April 2026.
- ESCO Technologies, ESCO completes acquisition of Megger Group Limited, 1 October 2026.
- Fortive, Fortive announces completion of the Ralliant separation, 30 June 2025; Ralliant, Qualitrol.
- Hitachi Energy, Our story.
