When registering rolling stock on specific Australian rail networks, operators must demonstrate compliance with relevant network standards and safety assurance processes.
EN 50155 is a European railway standard that specifies requirements for electronic equipment installed on rolling stock.
It ensures that such equipment can operate reliably under severe railway conditions – from wide temperature ranges, vibration and shock to electrical supply instability, humidity, and electromagnetic disturbances.
Australia does not adopt EN 50155 as mandatory law in the same way European Union (EU) member states use it under EU directives (e.g., the Railway Interoperability Directive).
However, EN 50155 is widely referenced in Australian rolling stock design specifications and contracts.
Engineering and procurement specifications (for example, for electrical and electronic assemblies on trains) often require compliance to EN 50155 or equivalent to ensure environmental and electromagnetic compatibility (EMC) performance.
State and operator technical standards (such as Transport for New South Wales’ equipment specifications) list EN 50155 among key international standards, and EMC compliance and test plans for rolling stock assets in Australia often use EN 50155 and EN 50121 as the framework for test conditions and acceptance criteria.
This means that, in practice, much Australian rolling stock procurement – especially where equipment is sourced from global suppliers – expects compliance to EN 50155 or demonstrated equivalence to meet technical requirements from the operator.
High-voltage transducer
Knick P45000 is a high-voltage transducer designed for measuring high DC (direct current) and AC (alternating current) voltages on heavy vehicles, especially rolling stock.
They are used for the monitoring and control of traction motors, or the monitoring of DC link voltage in traction power converters or on-board power converters.
In Australia, the German-manufactured product is available through ALVI Technologies, a New South Wales-based business that has more than 40 years of experience in the fields of electronic measurement and controls.
Archit Jha, Director of ALVI Technologies, told Rail Express that the Knick P45000 is the most space-saving high-voltage transducer for rolling stock.
“The transducer is very compact – you could probably fit three side-by-side compared to older versions,” he said. “The devices can even be mounted in a stack, allowing for very tight space requirements.
“The housing also offers flexible mounting options: upright or horizontal, screwed or snapped onto 35-millimetre DIN rails.”
With the Knick P45000, the voltage measurement input is highly isolated from output and auxiliary power, and the current output is compatible with commercially available control inputs.
The product is certified for use in Safety Integrity Level 2 (SIL2) systems and, redundantly, SIL3. Thus, for example, the presence of dangerously high voltages can be reliably detected.
It’s also robust due to its full vacuum encapsulation, and can withstand wide temperature changes and humidity, as well as vibration and shock.
“The Knick products are used in mining in Australia, and hold up very well in environments where there is a lot of dust and vibration,” Jha added.
ALVI Technologies recently supplied an Australian tram operator with 130 Knick P45000 transducers as part of a rolling stock upgrade.
“The product they had in the trams was from the 1980s, so it was time for an upgrade,” said Jha. “They didn’t need to replace the entire trams, so they are just installing new transducers.”
Jha said the Knick P45000 is designed with the high-voltage cables coming from the bottom, which makes carrying out upgrades easier.
“This design is the same as the design of the trams’ old transducers, so it’s been a faster process for the installers.
“This has saved them money and ensures that assets can be returned to service quicker.”
The P45000 high-voltage transducer is expressly certified for use on rolling stock according to EN 50155 (environmental and electrical requirements) and EN 45545 (railway fire protection) in its current form.
Manufacturers and operators can demonstrate their compliance to EN 50155 using the P45000’s certificate and declaration of conformity as part of technical compliance evidence in engineering specifications or procurement contracts.
Because EN 50155 is widely accepted in Australian rolling stock specifications, the P45000 can be considered compliant for use in Australian railway applications, provided other system-level requirements (functional safety, EMC, mounting, enclosure protection, etc.) are also satisfied in the specific installation.
Speed signal doubler
Another exciting product recently introduced to the Australian market by ALVI Technologies is the Knick P16800, an innovative speed signal doubler for safety-critical applications.
It is used for voltage and current measurement in rolling stock, signal isolation in rolling stock, and voltage and current measurement for DC traction power supply.
“Every train and tram has a speed sensor that is mounted somewhere near the wheels, that tracks how fast the vehicle is going,” Jha said. “Because there is so many different control systems on a train or a tram, they all need their own speed sensor. What happens is, there is not enough space to physically mount so many speed sensors. So Knick has created a speed sensor splitter, so you only need one but you can feed it three or four different control systems.”
The Knick P16800 pulse transducer safely separates signals from one or two speed sensors and duplicates them for other connected devices. It meets SIL 4 safety requirements and ensures the signals are transmitted safely without interfering with each other.
High isolation and double shielded optical signal transmission help protect the signals from interference and keep them accurate when they are duplicated.
To improve compatibility between the sensor and the controller, the P16800 can also convert current signals into voltage signals, or voltage signals into current signals. It can also reduce the output signal frequency by ratios of 2:1, 4:1, or 8:1.
