Marsun MHD250 250 kW Three-Phase Diesel Generator with ATS

The Marsun MHD250 is the most powerful of the three Marsun diesel generators MHD80, MHD100 and MHD250: three-phase 400 V, 250 kW rated (280 kW maximum), a 10,300 cm³ engine and a 1000 l tank, with which the manufacturer states about 24 hours of continuous running. The recommended continuous load is 187.5 to 200 kW, so it is meant for high-demand sites where the MHD80 and MHD100 would not have enough power; it weighs 2700 kg and measures 3600 × 1300 × 2000 mm. It has a built-in ATS, a Two-Wire Switch connection and Modbus monitoring.

Technical specifications

Download the manufacturer datasheet (PDF)

How the MHD250 differs from the MHD80 and MHD100

All three models have liquid cooling, a built-in ATS, a Two-Wire Switch connection, Modbus monitoring, 1500 rpm and a 72 dB noise level. They differ in power, engine, tank size and weight:

Choose the MHD250 if the continuous load is above 75 to 80 kW (the MHD100 range) or the unit must run a long time without refuelling (1000 l tank). For a smaller load the MHD100 (100 kW, 160 l tank, 1300 kg) or MHD80 (80 kW, 120 l tank, 1150 kg) are lighter and smaller, and their rated voltage is 230 V / 400 V, while the MHD250 datasheet gives 400 V only.

What is a 250 kW three-phase diesel generator used for?

The MHD250 is intended for backup power for homes and farms, building sites, solar systems with an energy storage battery, server rooms and other critical systems, and as the main source in an off-grid system. Of the three models, choose it when the continuous load reaches 187.5 to 200 kW or when it must run a long time without refuelling: with the 1000 l tank the manufacturer states about 24 hours.

How much fuel does the MHD250 use and how long does it run on a full tank?

The manufacturer states fuel consumption below 205 g/kWh. At a full 250 kW load that is 205 × 250 / 1000 = 51.25 kg of diesel per hour, or 51.25 / 0.84 ≈ 61.0 l/h (diesel density 0.84 kg/l). At that rate the 1000 l tank lasts about 16.4 hours (1000 / 61.0). This is a rough estimate based on the manufacturer’s maximum consumption figure.

The manufacturer states about 24 hours of continuous running. The real time depends on the load: the lower the load, the less fuel burned per hour. The datasheet does not say what load the 24 hours refers to. If you need to run longer without refuelling, you can choose an additional fuel tank.

Diesel generator with ATS and automatic start from a hybrid inverter

The MHD250 has a built-in ATS and a factory Two-Wire Switch connection (dry, voltage-free contact), so the generator can start and stop on its own.

• On a site without solar, the ATS watches the grid: when the voltage drops it starts the generator and switches the supply, and when the grid returns it switches back to grid power and stops the engine.
• With a hybrid or off-grid inverter, the generator is wired to the inverter’s generator input and the inverter decides when it needs the generator’s help.
• When the energy storage is depleted, the inverter sends a signal to the Two-Wire Switch connection, and the generator takes over the loads and charges the batteries.

Closing the contact starts the start-up procedure; opening it shuts the engine down safely. The manufacturer states compatibility with Deye, Solis, Solplanet, GoodWe, Victron Energy and Sungrow hybrid inverters. Operating parameters can be monitored remotely via Modbus without going to the unit. Connecting the generator to the building’s wiring and configuring the ATS must be done by a certified electrician.

How do you connect a backup generator to a house or site?

The MHD250 connects to the site’s internal wiring through a fixed connection, and a certified electrician configures the ATS. ESO (Lithuanian grid operator) states, in its recommendations for installing a backup source:

“A generator may be connected to the internal electrical network of a whole building only by installing a fixed connection and measures that ensure the voltage produced by the generator is not fed into ESO’s networks… Entrust this work only to qualified specialists.”

ESO — Recommendations for installing a backup power source

On the same page ESO advises choosing the power according to your connection capacity and, when connecting single-phase loads to a three-phase generator, taking the single-phase limit into account, because the datasheet gives the combined power of all three phases.

We handle it for you. We select the equipment for your site, deliver anywhere in Lithuania, install and connect it.

Three-phase 400 V power: how to spread the load

The MHD250 powers both three-phase 400 V and single-phase loads, but it does not give equal (full) power on a single phase. Spread single-phase loads as evenly as possible across all three phases and avoid a large imbalance.

When sizing the load, allow for starting currents: inductive loads such as pumps and compressors draw 2 to 5 times more current at the moment of start than when running.

Running at 100% power for a long time is not recommended. The optimum for engine and alternator life is 75 to 80% of rated power, which for the MHD250 is about 187.5 to 200 kW (a 25% power reserve). In a system with energy storage, add the power the generator will use to charge the batteries to the building’s demand.

What to know before buying

• Noise. The manufacturer states 72 dB. It is a diesel engine, so plan the position, ventilation and fuel storage in advance.
• Weight and size. The MHD250 weighs 2700 kg and measures 3600 × 1300 × 2000 mm. Unloading and moving it takes certified lifting straps or hoists of suitable capacity.
• Fuel tank. The tank holds 1000 l and the manufacturer states about 24 hours of continuous running; an additional fuel tank can be chosen as an option, and there is a heated fuel block and an additional fuel pump.
• Protection. No-load protection, overpressure protection, an overcurrent breaker, automatic shut-off at 10% fuel, AVR voltage regulation, and a frequency and voltage indicator.
• Inverter. If you already have a hybrid inverter, tell us the model and we will select the connection.

Frequently asked questions

How long does the Marsun MHD250 run on a full tank?

The manufacturer states about 24 hours of continuous running on the 1000 l tank. Our rough calculation for a full 250 kW load gives about 16.4 hours, because consumption is then about 61.0 l/h.

How much fuel does the MHD250 use?

The manufacturer states below 205 g/kWh; at a 250 kW load that is about 51.25 kg, or 61.0 l of diesel per hour. At a lower load, consumption per hour is lower.

Does the Marsun MHD250 have an ATS?

Yes. The MHD250 has a built-in ATS: when the grid voltage drops it starts the generator and switches the supply, and when the grid returns it switches back. No separate ATS device is needed.

Which inverters is the MHD250 compatible with?

The manufacturer lists Deye, Solis, Solplanet, GoodWe, Victron Energy and Sungrow hybrid inverters. Automatic start from the inverter runs through the Two-Wire Switch connection, and Hybrid Energy matches the exact wiring to your inverter model.

Can the MHD250 be connected straight to the house’s distribution board?

No. The MHD250 is connected to the building’s or site’s network only through a fixed connection with protection that stops voltage reaching the ESO grid, and only by qualified specialists.

Is a 250 kW generator suitable for a house, a farm or a construction site?

Yes. The manufacturer intends the MHD250 for backup power for homes and farms, construction sites, server rooms, and as the main source in off-grid systems. Hybrid Energy selects the power according to your connection capacity and real load.

How does the Marsun MHD250 differ from the MHD80 and MHD100?

The MHD250 is the most powerful: 250 kW (280 kW maximum), a 1000 l tank and 2700 kg, against 80 kW for the MHD80 and 100 kW for the MHD100. Its datasheet also gives 400 V only. Hybrid Energy helps you choose the model for your load.

Can single-phase appliances be connected to the MHD250?

Yes, the MHD250 also powers single-phase loads, but it does not give equal power on a single phase, so they must be spread evenly across all three phases.

What load is recommended for the MHD250?

About 187.5 to 200 kW, that is 75 to 80% of rated power; running at 100% for a long time is not recommended. Pumps and compressors draw 2 to 5 times more current at start-up, which must also be allowed for.

How much does the MHD250 weigh and how is it delivered?

The MHD250 weighs 2700 kg and measures 3600 × 1300 × 2000 mm, so unloading takes lifting equipment. Hybrid Energy delivers anywhere in Lithuania, installs and commissions it.

Sources

• Marsun MHD250 manufacturer datasheet (PDF), checked 2026-10-26
• ESO, recommendations for installing a backup source, checked 2026-10-26