Electric motor 250 kW, 990 rpm, 400 V / 690 V, 4LC-355L2-6 LV

For operations where reliability, energy efficiency and long-term economics matter, it is advisable to choose a motor precisely according to the load and speed class. The 4LC-355L2-6 model with an output of 250 kW operates in the range of 900-1000 rpm, so it naturally fits applications in which optimised operation has a significant impact on both consumption and the service life of the technology. In practice, this is a solution that helps deliver major cost savings in continuous service while also providing parameters suitable for large technological units.

This low-voltage asynchronous electric motor is designed for demanding industrial processes where stable operation, convincing efficiency and resistance to long-term thermal and mechanical loading are expected. An efficiency of 96.3% and a power factor of 0.86 help improve the energy balance of the drive, which is especially important in constant-duty operations with a high annual number of operating hours. For factories and drive integrators, it is also important that the manufacturer VYBO Electric works with its own research and development, so the range is focused on practical use in industry.

Efficient operation in the 900-1000 rpm range for large drives

In the speed segment of 900-1000 rpm, the motor offers a balance between torque and energy consumption, which is especially advantageous for drives with higher inertia or for applications with constant load. The nominal speed of 990 rpm is suitable where stable mechanical behaviour is required without unnecessary loss modes. The starting torque ratio Tst/Tn of 1.6 and the breakdown torque ratio Tmax/Tn of 2 show that the motor can handle starting and short-term overload in line with the requirements of heavy industrial operation.

During starting, the starting current ratio Ist/In of 8 must be taken into account, which is an important figure for starting design, protection and sizing of the power supply system. The rated current at the delta connection of 400 V is 433 A and at the star connection of 690 V it is 251 A, so the motor can be suitably incorporated into various voltage concepts according to the project. The noise level of 85 dB(A) is relevant for this power class when assessing acoustics in production halls and technological units.

A design that helps in aggressive environments

The frame size of 355 mm and the all-cast-iron design give the motor the mechanical robustness needed for pumps, compressors, conveyors and other heavy drives. The robust cast-iron construction helps absorb vibration, which improves operational stability and contributes to lower stress on the bearings, foundation and connected technology. It also increases corrosion resistance, which is important in aggressive environments with dust, moisture or chemical exposure.

The design detail in the form of 2-M63X1.5 cable entries makes it easier to connect power cables in distribution and motor cabinets. The DE bearing 6322-C3 and the NDE bearing 6322-C3 support long-term running accuracy under higher load, while the PTC winding protection accessory increases safety under thermal stress. These elements will be appreciated especially by an integrator who needs to design a reliable drive for a demanding production unit.

Industrial applications of the electric motor

• Pumps in heavy-duty operation benefit from stable torque and long-term reliability during continuous fluid transfer.
• Fans and blowers benefit from the 990 rpm speed class and the balanced energy balance.
• Compressors require high operational certainty and a torque reserve both at start-up and when the load changes.
• Conveyor systems in factories need smooth running and resistance to repeated loading.
• Mixing and homogenising units appreciate robust bearing arrangement and stability under dynamic shocks.
• Extruders and forming lines require precise power transmission under long-term thermal stress.
• Crushing and grinding equipment need high mechanical resistance and a suitable response during start-up.
• Rolling equipment uses a solid basis for power transmission in production cycles with high torque.
• Technological linear drives benefit from reliable operation in continuous processes.
• Large air conditioning and ventilation units benefit from stable running and low operating losses.

Parameters that make design and integration easier

When planning the drive, the packed weight of 1826 kg and the package dimensions of 1607*822*1161 mm are also important, as these data affect logistics, handling and installation preparation at the site of installation. The rotor inertia is not stated, so when designing the control strategy it is recommended to base it on the requirements of the specific machine and on the operational profile. For manufacturers of technological systems, it is an advantage that the motor has clearly defined power and voltage options for direct incorporation into the project.

If you need a motor for long-term industrial operation that combines efficiency, a robust cast-iron construction and practical service conditions, this model is a suitable candidate for extensive drive assemblies. Contact us if you would like to assess compatibility with your technology, and send us a non-binding enquiry.