For system integrators, panel builders, and engineering‑driven procurement teams, selecting a power supply is not only about wattage. It also involves thermal margins, EMC behavior, safety documentation. And whether the system passes acceptance testing without rework. In the world of industrial automation, where 48 V DC is increasingly used for distributed power architectures, motor drives. And high‑power sensors, the power source must be as compact and rugged as the equipment it powers.
The TPS 48V Open Frame Power Supply, based on the MPT120S-48V platform, engineered precisely for this environment. It is a compact, PCB‑mount AC/DC converter that delivers a regulated 48 V DC output with 3000 VAC isolation. All within a footprint of just 126 × 62 × 35 mm. Designed for seamless integration into larger control cabinets, machinery, and factory automation systems. It provides the safe, efficient, and reliable power that 24/7 industrial operations demand.
Why 48V DC is the rising standard for distributed industrial power
While 24 V DC has long been the dominant control voltage in factory automation, the trend is rapidly shifting towards 48 V. The reason is simple physics: for the same power, a 48 V system requires only half the current of a 24 V system. This dramatic reduction in current (I = P/V) leads to significantly lower I²R losses in cabling. Which allowing for smaller wire gauges and longer cable runs between cabinets. This makes 48 V ideal for powering high‑power actuators, integrated servo drives. And Power‑over‑Ethernet (PoE++) devices that require more than the 30 W provided by 24 V systems.
A dedicated industrial 48V open frame power supply is the most efficient way to generate this voltage directly from the AC mains. Integrating such a supply directly onto the main control board eliminates the need for a separate DIN‑rail unit, saving space, reducing wiring complexity, and improving system reliability. This is the foundation of modern, decentralized factory automation. For a broader look at how such integration fits into overall manufacturing, see the TPS open frame and enclosed power supply category.
Introducing the TPS-MPT120S-48V: a high-voltage input, compact power module
The TPS-MPT120S-48V is a 120 W, single‑output open‑frame AC/DC power supply. It is a critical member of the TPS High Voltage Series. Which designed to operate directly from the high‑voltage AC mains common in industrial environments. Its defining feature is an exceptionally wide input range of 176–500 V AC. Which meaning it can connected directly to a single‑phase of a 208 V, 400 V. Or even 480 V supply without the need for a step‑down transformer. This simplifies global inventory for OEMs, as a single part number can deployed across different regional grid voltages.
With a rated output of 48 V at 2.5 A under natural convection, it provides ample power for logic circuits, communication gateways, and smaller motor drives. Its open‑frame design is intentional, allowing it to treated as a component on the system PCB rather than a standalone box. This design philosophy explored in more detail with other models in the range, such as the TPS‑MPT24S‑5V and the higher‑power TPS‑GSH225S‑12V.
Electrical performance: wide input, high efficiency, and adjustable output
The ultra‑wide AC input range of 176–500 V AC is a game‑changer for global machine builders. At low‑line conditions (100–176 V AC), the unit operates with a 50 % power derating. Which ensuring it can still function during severe brownouts. The power supply’s efficiency is typically 88 %, reducing internal heat dissipation and contributing to a longer operational life for itself and surrounding components. Output voltage is adjustable from 46 V to 52 V, allowing engineers to compensate for voltage drops in long cable runs. Which ensuring a precise 48 V is delivered to the load.
Output ripple and noise are critical for sensitive industrial electronics. The TPS-MPT120S-48V achieves a maximum ripple of just 100 mV peak‑to‑peak, ensuring a clean power source for analog sensors and high‑speed digital controllers. This low‑ripple design achieved through a combination of a stable switching topology and high‑quality output filtering capacitors.
Protection functions for harsh industrial environments
Factory floors are electrically unforgiving. Power surges, overloaded outputs, and short circuits are common occurrences. The TPS-MPT120S-48V equipped with a comprehensive suite of protection functions to ensure both its own survival and the safety of the connected load. These functions designed for automatic recovery. Which is essential for minimizing downtime in unmonitored remote installations.
The output short‑circuit, over‑current, and over‑voltage protections all operate with hiccup or restart modes, automatically attempting to restore normal operation after a fault cleared. Additionally, it features an input under‑voltage lockout and over‑temperature protection with auto‑recovery. These robust defense mechanisms, summarized in the diagram below, guarantee reliable 24/7 operation in demanding industrial settings.
Mechanical integration: open‑frame design, mounting, and cooling
Measuring a compact 126 × 62 × 35 mm and weighing only 290 g, the TPS-MPT120S-48V is an ultra‑compact power module designed for embedded applications. The open‑frame, PCB‑mount design provides maximum flexibility for system integrators. It can mounted directly onto the main system board as a daughter‑card, or secured with standoffs inside a control cabinet. This eliminates the volume and cost of a redundant outer case and allows the host system’s enclosure to provide the final touch protection and environmental sealing.
The unit designed for natural convection cooling, which eliminates fan noise. Reducing a common point of mechanical failure, and simplifies maintenance. System designers must, however, ensure that the module has adequate clearance and airflow within the final enclosure to stay within its operating temperature range of -25 °C to +60 °C.
Compliance and safety: IEC 62368‑1, EMC, and 3000 VAC isolation
For CE marking of industrial machinery, the integrated power supply must meet stringent safety and EMC standards. The TPS-MPT120S-48V designed and tested to comply with IEC 62368‑1, the hazard‑based safety standard for AV, ICT, and industrial equipment. A critical safety feature is its 3000 VAC input‑to‑output isolation. This reinforced insulation provides a safe and reliable barrier between the hazardous AC mains voltage and the accessible SELV (Safety Extra‑Low Voltage) output, protecting both operators and sensitive downstream electronics.
Furthermore, electromagnetic compatibility guaranteed by compliance with CISPR 32 / EN 55032 Class A. This ensures the power supply will not generate excessive electromagnetic interference that could disrupt nearby control systems or communication networks. TPS provides a Declaration of Conformity with each product, streamlining the system integrator’s CE documentation process.
Application guidance for factory automation and motor drives
- Integrated Motor Drives: Powering the logic and gate‑drive circuits of compact servo and stepper motor drives directly from the DC bus.
- Distributed I/O and Fieldbus Modules: Providing a stable 48 V rail for remote I/O blocks and communication gateways (e.g., PROFINET, EtherCAT) in a compact form factor.
- High‑Power Sensor Systems: Supplying clean power to laser scanners, vision systems, and radar sensors used in modern smart factories.
- IoT and Edge Gateways: Powering embedded computing gateways that aggregate data at the edge of the industrial network.
RFQ checklist for 48V open frame power supplies
- Power requirement: Confirm that the 120 W continuous output meets the load demands with a 20–30 % safety margin.
- Input voltage: Verify the local AC mains voltage is within the 176–500 V AC range (or 249–707 V DC).
- Output adjustment: Is the 46–52 V adjustment range sufficient to compensate for voltage drops?
- Thermal environment: Will the ambient temperature in the enclosure be below 60 °C?
- Certifications: Is IEC 62368‑1 compliance required for the end product? Is EN 55032 Class A EMC sufficient?
- Quantity and schedule: Prototype, pilot, and series volume requirements.
Browse TPS 48V open frame power supplies and request a quote →
Frequently Asked Questions
What is the main advantage of a 48V open‑frame supply over a 24V one?
A 48V system uses half the current for the same power, reducing wiring costs, lowering I²R losses, and enabling longer cable runs, which is ideal for large factory installations.
Can the TPS-MPT120S-48V be used in a fanless, sealed enclosure?
Yes, it designed for natural convection cooling. However, the system designer must ensure the ambient temperature inside the sealed enclosure does not exceed the unit’s 60 °C rating at the expected load.
What does “3000VAC isolation” mean for my system?
It means the input and output sides are galvanically isolated with a reinforced insulation barrier tested at 3000 V AC. This is a critical safety feature that protects users from electric shock and protects sensitive electronics from mains‑borne transients.
Does the open‑frame design mean I need an extra safety enclosure?
Yes. The open‑frame PSU is a component intended for integration into a final system. The host equipment’s enclosure provides the required protection against accidental contact with hazardous voltages.
Where can I find the complete technical specifications?
Detailed datasheets and compliance certificates are available on the TPS open frame power supply product page.
