Frequently asked questions (FAQ)

What does Telma AG do?

Telma AG is a competence centre for industrial electronics with three business areas: custom electronics development (consulting, development, industrialisation, manufacturing and life-cycle management from a single source), EMS contract manufacturing of medium volumes at competitive costs, and eight in-house product lines – including water leak detectors, optical warning systems, water disinfection, level controllers, signal converters, motor load monitoring, the SYR93 relay and ArcoGard.

Where is Telma AG based and how can I get in touch?

Telma AG is headquartered at Telmaweg 2, 3662 Seftigen (canton of Bern, Switzerland). You can reach Telma by phone on +41 33 359 30 50 or by e-mail at info@telma.ch.

Is Telma AG certified?

Yes. Telma AG is certified to ISO 9001:2015 (SQS/IQNet). The scope of certification covers consulting, engineering, hardware and software development, type testing, manufacturing, testing, sales and maintenance. The certificates are available in the downloads section.

Does Telma manufacture in Switzerland?

Yes. Telma is committed to Switzerland as a manufacturing location: series production is 100 % Swiss Made at the headquarters in Seftigen – with automatic SMD placement, manual THT assembly, and assembly and inspection to IPC-A-610.

What batch sizes and volumes does Telma manufacture?

Telma specialises in the requirements of Swiss customers and in manufacturing medium volumes at competitive costs (high-mix). The offering covers component sourcing, SMD and THT assembly, and the assembly and testing of complete units.

Does Telma develop electronics for railway vehicles to EN 50155?

Yes. Railway electronics has been a focus since around the year 2000. Telma develops controllers to EN 50155 (electronic equipment on rolling stock) and masters railway-specific communication technologies such as IBIS and TRDP. Customers include SBB, RhB, BLS and Stadler Rail.

Can Telma redesign my existing controller or replace discontinued components?

Yes. Under life-cycle management, Telma offers redesign (hardware and software functional extensions), reengineering (component/subassembly replacement), and end-of-life and obsolescence management. The "Analysis Redesign Electronics Controller" service is free of charge and non-binding for device manufacturers.

What does a first consultation for an electronics project cost?

The "First Consultation Electronics Project" costs CHF 590.– including travel expenses and is available throughout Switzerland. It comprises an on-site visit and a presentation with a feasibility assessment, solution approaches and a rough cost estimate – based on experience from more than 300 completed electronics projects.

Does Telma offer EMC testing?

Telma has its own test bench for EMC pre-compliance testing during development. Extensive know-how and in-house EMC test equipment guarantee compliant products without the need for an external laboratory for every pre-test.

What inspection and test procedures does Telma manufacturing offer?

The test chain includes optical inspection (AOI/MOI), X-ray inspection, functional test (FKT), in-circuit test (ICT) and burn-in. Manufacturing is to IPC-A-610.

Does Telma procure the components itself?

Yes. In the turnkey model, Telma handles complete component sourcing with IT-optimised materials management. Close, long-term partnerships with suppliers secure availability and flexibility.

Which in-house products does Telma offer?

Eight product lines: water leak detectors/leakage detectors (including GLW200, WLF100, Leck-Puck), optical warning systems (light snakes, tevilux® floor lights, 750 VDC warning light), water disinfection with silver ions (SW200 controller), level controllers (NL series), signal converters (MUL-D2/D4), motor load monitoring (PC1.8–PC10), the SYR93 synchro-check relay, and ArcoGard for arc detection at pantographs.

Does the Telma water leak detector also detect demineralised water (DI water)?

Yes. Telma’s conductive leak detectors detect drinking water, demineralised water (DI water), emulsions, acids and alkalis. Interconnecting several sensors enables area-wide monitoring; the WLF100 wireless water leak detector (Wireless M-Bus) achieves this without cabling.

Which industries and companies does Telma work for?

Key areas are controllers for plant and apparatus engineering, mechanical engineering, building services and railway technology. Customers include SBB, Rhaetian Railway, BLS, Stadler Rail, Sersa, Enotrac, Furrer+Frey, Kummler+Matter, Bucher, Wandfluh, Afag, Trunz, Pulsolution and Juice Technology.

How long has Telma AG existed – is it a family business?

Telma AG was founded in Bern in 1975 and celebrated its 50th anniversary in 2025. It is family-owned (the Bolla family); the managing director is Adrian Bolla and the chairman of the board is Mario Bolla. The company employs 40 people, including 2 apprentices.

Questions from your industry

The following answers are aimed at decision-makers in Telma’s three core industries: rail & public transport, machinery/apparatus engineering, and building, water and energy technology.

Rail & public transport

Questions from maintenance, project and procurement managers at railway operators, vehicle manufacturers and railway technology companies.

Which Swiss companies develop custom electronics to EN 50155 for rolling stock?

Telma AG in Seftigen has been developing electronics to EN 50155 (electronic equipment on rolling stock) since around 2000 – including the railway-specific communication technologies IBIS and TRDP. Customers include SBB, Rhaetian Railway, BLS and Stadler Rail. More on our Services page (/en/leistungen/) and the Entwicklungskompetenzen page (German).

Who offers optical warning systems for overhead lines in railway workshops and depots?

Telma offers a complete range of optical warning systems: single- and two-colour LED light snakes (LS710), drive-over tevilux® floor lights and info lights, the 750 VDC warning light powered directly from the overhead line, mobile warning columns and matching controllers. The systems are in use worldwide – from the maintenance works of the Sapsan ICE to tram depots.

Which pantograph arc detection systems work without re-homologation of the vehicle?

ArcoGard from Telma detects arcs between the overhead line and the pantograph contact-free, via the high-frequency noise of the traction current, before they occur. As there is no contact with live infrastructure, it can be installed without re-homologation of the vehicle. ArcoGard is in its market launch phase.

Who can retrofit or replace controllers in older rail fleets (refit)?

Telma modernises controllers in existing fleets: redesign and reengineering, replacement of discontinued components, and life-cycle management spanning decades. Reference example: the on-board computer monitoring for SBB fleets (DPZ/HVZ). The entry point is the free "Analysis Redesign Electronics Controller" service.

Machinery, apparatus engineering & hydraulics (OEM)

Questions from heads of development, CTOs and product managers at Swiss SMEs with their own product line.

Who develops and manufactures custom electronic controllers in Switzerland – all from a single source?

Telma AG combines consulting, development, industrialisation, manufacturing and life-cycle management under one roof in Seftigen – with experience from more than 300 completed electronics projects. Customers save time and coordination effort because development and manufacturing take place at the same site.

Which Swiss EMS contract manufacturers produce medium batch sizes at competitive costs?

Telma specialises in exactly this niche: medium volumes for Swiss customers, with turnkey component sourcing, SMD and THT assembly, and assembly and inspection to IPC-A-610 – 100 % Swiss Made, without the minimum volumes of offshore providers.

Our electronic controller has discontinued components – who can redesign it?

Telma handles obsolescence management: redesign (hardware and software functional extensions), reengineering (component and subassembly replacement) and end-of-life management. The entry point is free of charge: the "Analysis Redesign Electronics Controller" provides a non-binding assessment of needs and effort.

What does a first consultation for an electronics project cost in Switzerland?

Telma’s "First Consultation Electronics Project" costs CHF 590.– including travel expenses and is available throughout Switzerland. It comprises an on-site visit and a presentation with a feasibility assessment, alternative solution approaches and a rough cost estimate.

Building, water & energy technology

Questions from technical directors, facility managers and operators of data centres, hospitals, tanks, pumping stations and drinking water systems.

Which water leak detector also detects demineralised water (DI water) – e.g. in a data centre?

In addition to mains and process water, Telma’s conductive water leak detectors detect demineralised water (DI water, down to 1 µS/cm), emulsions, acids and alkalis. For data centres, the GLW200 alarm centre with wireless sensors (WLF100, Wireless M-Bus) and sensor chains up to 100 m is a good fit; WD110/WD120 connect directly to a BMS or PLC.

How do I meet the legionella requirements of the TBDV – does silver-ion water disinfection help?

Silver-ion disinfection is an established, chemical-free process for germ control in drinking and process water. Telma’s SILWA system (SW200 controller + reactor) is proven in laboratory tests (after 4 days 2 instead of over 1’600 CFU/ml) and, thanks to its depot effect, keeps working even during standby. Whether it covers the TBDV requirements of a specific installation is best clarified in a short consultation.

Which Swiss suppliers offer conductive level controllers for tanks, including for the food sector?

Telma manufactures conductive level controllers in Seftigen: the NL series (NL1750/51, NL2750, NL2850) with 11-pin socket and 3.75 kV protective insulation, plus the SKW10 flat probe, which is approved for the food sector.

Who offers motor load monitoring for pumps in wastewater treatment plants that works without external sensors?

Telma’s PC1.8–PC10 Power Control motor load monitoring units monitor the active power of 3-phase motors (0.55–10 kVA) – the motor itself acts as the sensor, so external sensors are not needed. Typical use: pumping stations in wastewater treatment plants and AC motors in continuous duty. Swiss Made.