Monitor cell voltage compactly and safely

The new differential analog input module expands the u-remote remote I/O system with a solution for monitoring individual cells and cell groups. Weidmüller has succeeded in accommodating 15 differential analog inputs within a module width of just 11.5 mm, while achieving an isolation strength of up to 1,500 VDC. An integrated, switchable jumper simplifies the cascading of multiple modules—eliminating the need for double terminal assignments—thereby laying the foundation for efficient processes, early fault detection, and predictive maintenance.

Reliable monitoring of fuel cells and electrolyzers

The new u-remote module offers particular advantages for the hydrogen industry. To fully leverage the potential of hydrogen production and reconversion into electricity, operators require one thing above all: transparent and stable operating conditions for their systems. Continuous monitoring of individual cell voltages within electrolyzer stacks and fuel cells is a crucial component in achieving this.

Electrolyzer stacks and fuel cells consist of numerous individual cells connected in series. If the performance of even a single cell drops—due to degradation or local overload, for instance—it affects the entire stack. Consequently, anomalous cell voltages serve as a reliable early indicator of impending cell reversal, uneven aging, local hotspots, membrane or contact issues, and operating conditions involving increased wear or efficiency loss.

The new u-remote module performs differential measurements between pairs of channels, thereby precisely capturing the voltage of individual cells or cell groups. It does this by measuring the voltage difference between two consecutive channels connected, for example, to the terminals of a cell within a stack. Up to 15 individual cell voltages can be monitored per module, which features 16 connection points. Thanks to reinforced isolation of up to 1,500 VDC, even large stacks can be monitored without additional protective measures. In electrolysis stacks, the cell voltage is typically between 1.7 V and 2.2 V per cell (for PEM electrolysis). Consequently, up to 880 cells can ideally be monitored within a single u-remote station. This is made possible by support for up to 64 active I/O modules per fieldbus coupler, which reduces both complexity and costs.

This enables operators to identify critical trends at an early stage and respond proactively via their control systems—ranging from automated load reduction to the controlled shutdown of the affected stack.

Increasing system reliability through measurement data

Continuous cell voltage monitoring helps operators detect abnormal cell conditions early on, making maintenance planning more efficient and cost-effective. Condition-based maintenance becomes possible, replacing fixed, blanket maintenance intervals. The data collected by the u-remote module forms the basis for integrating hydrogen systems into the Industrial IoT, opening up opportunities for predictive maintenance, remote maintenance, and condition monitoring. In the long term, this helps avoid unplanned downtime, extend stack service life, and reduce efficiency losses.

Direct integration with Weidmüller’s u-mation hardware and software solution facilitates cloud and edge integration for the hydrogen system. Measurement data from cell voltage monitoring can be visualized and analyzed in real time and utilized for predictive maintenance strategies. Furthermore, u-mation’s open architecture enables seamless connectivity with various IoT platforms and industrial communication protocols. This fosters efficient process control, simplifies integration into existing automation environments, and lays the foundation for the digital transformation of hydrogen production. Easy configuration

The u-remote remote I/O system offers exceptional flexibility thanks to its modular design. Electronic modules can be replaced or added without dismantling the entire station—making it ideal for retrofitting or functional upgrades. An integrated web server enables convenient parameterization, diagnostics, and the loading or saving of configurations. The cell voltage input can be configured to meet specific user requirements. This flexibility allows for the monitoring of individual cells or defined groups of cells. A wide range of voltage ranges is supported, such as the low-voltage ranges of 0–3 V or 0–30 V. Alternatively, the system can handle very large differentials, ranging from -100 V to +100 V. Fieldbus couplers and gateways for common fieldbus and Industrial Ethernet protocols—such as Profinet, EtherCAT, Modbus TCP, and EtherNet/IP—enable deployment in heterogeneous systems.

A u-remote I/O station can be expanded modularly to include up to 64 different accommodate modules. This allows even complex measurement and control tasks to be implemented flexibly and individually—a decisive advantage, particularly given the evolving requirements of hydrogen technology. It enables users to tailor the station precisely to their specific needs without compromising on scalability or adaptability.

Furthermore, the system meets rigorous safety and quality standards: the u-remote solution holds all necessary certifications, including CE, ATEX, IECEx, UL, and DNV. This makes u-remote highly versatile, suitable for use in global markets as well as in environments with specialized requirements, such as ATEX Zone 2. This significantly expands the technology's range of applications and provides added investment security.

Designed for a growing hydrogen industry

As standards, requirements, and operating strategies within the hydrogen industry continue to evolve, operators benefit greatly from modular systems. The u-remote I/O system can be adapted to changing needs—for instance, through new electronic modules or additional diagnostic functions—thereby supporting the rapid industrial ramp-up of the hydrogen economy.

With solutions like the u-remote I/O system, Weidmüller is expanding its existing stack monitoring capabilities to include fuel cell monitoring. Comprehensive data acquisition solutions are now available—covering everything from H2 generation and power conversion to battery energy storage. Through these extensive solutions, Weidmüller supports operators and manufacturers of hydrogen systems across the entire lifecycle, from planning and commissioning to ongoing operation.