Power supply stability is essential for safe and reliable operation. Voltage fluctuations, surges, and power interruptions are more than simple inconveniences: they impair the performance of sensitive equipment, trigger unplanned downtime, and generate direct financial losses for production.
Faced with this scenario, engineers, designers, integrators, and managers face a clear challenge: designing systems capable of absorbing electrical failures without compromising data integrity or operational continuity. This becomes even more critical in environments with high levels of electromagnetic interference, dust presence, and wide temperature variations, conditions that test the limits of any electrical infrastructure.
Given this reality, power supplies have taken on a strategic role in protecting systems. Beyond delivering stable energy, they contribute to connectivity, monitoring, and real-time diagnostics, thereby increasing the availability and safety of industrial operations.
Now, the new Nexto HX (Xtorm) power supplies enter the market to further expand this strategic role of power supplies in operational safety. Featuring resources such as fiber optics and redundancy, these models were developed to boost the reliability of the electrical infrastructure, reduce downtime risks, and offer greater visibility into the status of the systems’ power supply.
In the following sections, discover the new models in this series.
The evolution of power supplies for automation
To meet these demanding high-availability requirements, Altus has expanded its Nexto HX (Xtorm) series portfolio with two new redundant power supply modules: the HX8305 and HX8325 models.
Developed for highly critical and high-availability control systems, these two power supply models deliver up to 60 W of active power directly to the chassis internal backplane, with a maximum output current of 12 A to power the CPU and other input/output (I/O) modules. The two models differ by their input voltage range:
- – HX8305: designed for standard direct current control networks, it operates with a nominal input voltage of 24 Vdc, featuring a dynamic range of 19.2 to 30 Vdc.
- – HX8325: developed for electrical sector applications and large substations, it operates with a nominal input of 125 Vdc, featuring a dynamic range of 100 to 150 Vdc.
Native operation at 125 Vdc is a critical differentiator for the power market. Electrical substations rely on robust battery banks within this voltage range to keep protective circuit breakers and control systems active, even during a total AC grid blackout. By eliminating intermediate converters, the HX8325 module reduces the number of components prone to failure, saves DIN rail space, and optimizes installation efficiency.
See the specifications that demonstrate the high level of ruggedness of these solutions:
| Characteristic | HX8305 | HX8325 | Benefit |
| Input voltage | 24 Vdc (19.2 to 30 Vdc) | 125 Vdc (100 to 150 Vdc) | Power supply flexibility. |
| Maximum output power | 60 W | 60 W | High load capacity in an optimized design. |
| Hold-up time | 10 ms | 10 ms | Guarantees operational continuity even during input voltage fluctuations. |
| Galvanic isolation | 2500 Vac per 1 minute | 2500 Vac per 1 minute | Rugged protection that isolates the logic control backplane against high-voltage surges. |
| Maximum output current | 12A 30 Vdc | 5A 125 Vdc | Prevents the tripping of protective circuit breakers and fuses during initial power-up. |
| Operating temperature | – 5 to 70 °C | – 5 to 70 °C | Thermal reliability for installation in non-climate-controlled locations. |
| Input protection | Internal 5A fuse | Internal 1A fuse | Fuse accessible directly on the front panel to simplify maintenance. |
Unlike conventional power supplies that act as isolated components within the system, the Nexto HX (Xtorm) series combines three functions into a single module: power supply, fiber-optic backplane expansion, and advanced hardware diagnostics.
Integrated backplane expansion with SFP and loopback
In medium and large-scale architectures, the connection between the main chassis (where the CPU resides) and the distributed I/O chassis typically requires coupler modules and media converters dedicated to each chassis, increasing installation complexity.
The HX power supplies eliminate this barrier by incorporating two SFP ports directly on the front panel. Furthermore, they save panel space by eliminating the need for dedicated converters. Through Gigabit fiber optics, the power supply module itself extends the internal backplane at a rate of 1.25 Gbps. Optical transmission offers total immunity to electromagnetic interference, eliminating risks along parallel cable routes and power lines.
These connections can be configured into three distinct architectures:
– Expansion without loopback (linear): the remote chassis are interconnected sequentially, with the optical output cable of each chassis connected to the input of the next chassis.
– Expansion with loopback (redundant ring): the output port of the last remote chassis is connected back to the input of the main chassis, forming a ring. If an optical cable is severed, the CPU detects the fault and instantly reroutes the data flow in the opposite direction of the ring. The control system maintains continuous access to process information and generates a diagnostic alarm, allowing corrective maintenance to be scheduled while the plant is fully operational.
– Power supply redundancy and expansion with loopback: two HX8305 or HX8325 power supplies are installed side-by-side in slots 0 and 1 of each chassis, forming an active-active setup in hot-standby. Both power supplies share the load evenly. In the event of an electrical failure or disconnection of one unit, the other unit assumes the full load, ensuring maximum fault tolerance for both the power supply and the communication backplane.
Local and remote diagnostic technology
One of the biggest bottlenecks in industrial maintenance is identifying field faults without the proper tools. The Nexto HX (Xtorm) series prevents this problem with a set of integrated diagnostic features:
– One Touch Diag (OTD): with a single press of the module’s diagnostic button, you can view all power supply status information on the CPU display without needing to connect a computer or laptop to the panel.
– Electronic Tag on Display (ETD): displays the logical identification (tag) and the registered description of the module directly on the controller’s graphic screen. This drastically reduces the risk of human error during field interventions and eliminates the need to consult paper wiring diagrams.
– Advanced Variable Diagnostics: all operating logical and physical parameters are mapped into process variables accessible by the application or supervisory systems (SCADA). It is possible to remotely monitor the exact internal temperature of the power supply, temperature alarms starting at 110 °C, input voltage drops, output voltage drops, and detailed failures in the SFP transceiver, such as a short circuit or loss of optical signal.
– Integrated Signaling Relay: an NO dry contact acts as a physical interlock. In operation, the contact remains closed; any internal anomaly or shutdown opens the circuit, enabling the triggering of alarms on auxiliary panels or the locking of safety circuits.
– Diagnostics via the CPU Web Page: another way to access diagnostic information is through the integrated web interface. The series CPUs feature an embedded web server that provides real-time status, monitoring, and diagnostic information. These pages can be accessed by any web browser, making it easy to check and analyze the operational conditions of the system.
Operations that benefit from the use of redundant power supplies
The rugged characteristics of the HX8305 and HX8325 power supplies deliver operational advantages across various segments of the industrial market:
– Power Generation, Transmission, and Distribution Systems (GTD): substations, wind farms, and solar plants encounter high levels of electrical noise generated by high-voltage circuit breaker switching. The 2,500 Vac isolation of the HX power supplies, combined with the fiber-optic communication network, immunizes the control system against these destructive transients. Native 125 Vdc powering also reduces reliance on auxiliary power supplies and simplifies integration into plant systems.
– Water and Wastewater Applications: water treatment plants (WTPs) and sewage pumping stations operate with pumps distributed over large areas. The expansion of the I/O backplane via single-mode or multi-mode SFP enables centralized control of multiple wells or channels without performance degradation and without the need for external network modems.
– Mining and Steel Industries: in crushers and ore conveyor belts, intense mechanical vibration and airborne conductive dust are constant challenges. The design, free of moving parts, prevents particle buildup inside the module, while the conformal coating protects internal circuits against oxidation.
– Process Industries and Oil & Gas: refineries and oil platforms demand redundant architectures to eliminate any risk of operational downtime. Combining power supply redundancy within the same chassis with loopback ensures operational continuity even when faced with multiple simultaneous cable or hardware failures.
– Machine Builders (OEMs): compliance with the IEC 61131-2 standard ensures that electrical panels satisfy all normative requirements for electromagnetic compatibility and electrical safety in a simplified manner.
The reliability of an industrial automation system is directly linked to the robustness of its power architecture. The new redundant power supplies in the Nexto HX (Xtorm) series redefine this standard by combining three fundamental pillars into a single compact and modular device: stabilized power supply, Gigabit connectivity via fiber optics, and advanced diagnostic features for the automation market.
By enabling preventive thermal monitoring and allowing communication faults to be corrected without interrupting the control process, the HX8305 and HX8325 modules become much more than simple panel components.
For industries that must prioritize productivity, safety, and the reduction of costs associated with unplanned downtime, these devices represent a strategic decision, and increasingly, an inevitable choice.
