25 kW grid-connected inverter model AU25K3P

In the world of commercial solar projects and factory rooftop installations, maximizing output power within a limited installation area is a key principle. However, achieving this typically requires using heavy, bulky, and expensive inverters. Austa has completely changed this equation with the introduction of the 25kW three-phase inverter model AU25K3P.

This device, the most powerful member of the AU15–28K3P series, is considered a true engineering masterpiece in compact design. This on-grid, transformerless inverter not only delivers an impressive efficiency of 98.8%, but also packs its full 25kW power into a body weighing an incredible 18 kilograms.

In this comprehensive analysis, we show you why the AU25K3P is the smartest choice for maximizing return on investment (ROI) in mid-scale three-phase solar projects.

A revolution in installation: 25kW of power, only 18kg of weight!

The most surprising competitive advantage of the AU25K3P is its weight. While typical 25kW inverters on the market weigh 30, 40, or even 50 kilograms, this model weighs only 18kg. Its dimensions (427×439×212 mm) are exactly the same as the 15kW and 20kW models.

What does this “flexible design” offer you?

• Significant reduction in installation costs: This device can easily be carried and installed by just one person (Manual Installation). This drastically reduces labor hours and eliminates the need for multi-person installation teams or lifting equipment.
• Lower logistics costs: Transporting and handling this inverter at the project site becomes much easier and cheaper.
• Easy maintenance: If servicing is needed, disassembly and replacement can be done with minimal effort and cost.

Technical advantages of the AU25K3P Inverter

The AU25K3P is not only lightweight—it is also very powerful from a technical standpoint.

1. Maximum efficiency of 98.8%

Thanks to its advanced transformerless design, energy loss is minimized. The AU25K3P offers:

• Maximum efficiency: 98.8%
• European efficiency: 98.2%

The European efficiency of 98.2% ensures that the inverter performs close to its maximum even under real-world, fluctuating weather conditions—not just during peak sunshine. This means less energy loss and greater income from electricity generation.

2. MPPT flexibility with asymmetric current input

This model features 2 independent MPPT trackers, and each MPPT supports 2 panel strings (a total of 4 strings). The interesting technical point is its asymmetric input current:

• Maximum DC input current: 36A / 30A

This means MPPT 1 can accept up to 36A, while MPPT 2 can handle up to 30A. This gives system designers extraordinary flexibility, especially for rooftops with irregular layouts where higher-current panels or different string configurations may be needed on one MPPT.

3. High DC Oversizing capacity (1.5x)

The AU25K3P has a rated AC output of 25kW but can accept up to 37.5kW of DC solar panels. This 1.5× DC oversizing capability is a major economic advantage, allowing the inverter to operate at its full 25kW capacity during early morning, late afternoon, and cloudy conditions—resulting in a much broader and more profitable energy production curve throughout the day.

4. Industrial-grade durability (IP66)

This device is built for operation under the toughest environmental conditions. With an IP66 protection rating, the inverter is completely resistant to dust and high-pressure water jets. Its wide operating temperature range (−25°C to +60°C) and intelligent forced-air cooling system guarantee stable performance and long lifespan in any climate.

“As a solar EPC contractor, transporting a 25kW inverter to a factory rooftop has always been a logistical challenge. The AU25K3P, with its 18kg weight, has turned this challenge into a joke. It directly reduces our installation costs, and its 98.8% efficiency fully satisfies our clients.”

Technical Specifications of the Austa AU25K3P Inverter

Below are the key technical specifications of this model based on the official datasheet:

Complete safety and grid compatibility (Grid Friendly)

The AU25K3P inverter complies with all international safety standards (such as EN/IEC 62109) and grid-connection standards (such as EN 50549). It is equipped with a complete set of protections, including active and passive anti-islanding, reverse DC polarity protection, short-circuit protection, and over-voltage and over-current protection. It also supports full control over active and reactive power to maintain grid stability.

For understanding the importance of IP ratings and the durability of electrical equipment in industrial environments, refer to the guide by the International Electrotechnical Commission (IEC).

FAQ

1. What types of projects is the AU25K3P 25kW inverter suitable for?
It is ideal for medium-scale commercial projects, factory rooftops, office complexes, and any site requiring three-phase 400V power with a 25kW capacity.

2. Is the 18kg weight truly an advantage for a 25kW inverter?
Yes, it is a revolutionary benefit. Most 25kW inverters weigh between 30 and 50kg. The 18kg weight significantly reduces labor, logistics, and installation time.

3. What is the benefit of the 36A/30A asymmetric input current in the MPPTs?
This allows designers to use slightly different array configurations or higher-current panels on one MPPT without reducing the system’s overall efficiency.

4. What is the maximum panel capacity that can be connected to this inverter?
You can connect up to 37.5kW of solar panels (DC) to this 25kW AC inverter. This 1.5× DC oversizing capability maximizes production during low-light hours.