FB3G250-24GL-91 DC Backward Centrifugal Fan, 24VDC, 250mm, 1716 m3/h

The FB3G250-24GL-91 is a 24VDC high-airflow DC backward centrifugal fan delivering an outstanding 1716 m³/h at 605 Pa static pressure — the highest airflow in the 250mm series. Operating at 2750 RPM, this fan is engineered for applications where maximum air movement from a compact low-voltage DC platform is essential. The BLDC92 brushless motor achieves this high output while drawing only 6.25A at 150W, with an integrated FG tach output enabling precision closed-loop speed control. Compatible with 0-10VDC analog and PWM digital control signals, it integrates seamlessly into automated ventilation and cooling systems. With IP44-rated ingress protection, Class B insulation rated to 130°C, and a 50,000-hour L10 service life, this fan is built for continuous-duty operation in demanding environments. Ideal applications include data center rack cooling, telecom infrastructure ventilation, industrial enclosure air displacement, solar-powered greenhouse circulation, and battery storage thermal management. CE and RoHS certified.

At the core of the FB3G250-24GL-91 is a BLDC92 external rotor brushless DC motor driving a backward curved centrifugal impeller with a 250mm diameter, optimized for high-volume airflow at 2750 RPM. The aerodynamic design achieves 75-80% efficiency, converting 150W of DC power into 1716 m³/h at up to 605 Pa — delivering substantial air movement while consuming 30-40% less energy than equivalent AC centrifugal fans. Operating across a wide 16-28 VDC input range at just 6.25A, it maintains stable performance through battery discharge cycles, enabling reliable operation in solar-direct and battery-buffered DC systems. The comprehensive control interface accepts 0-10VDC analog signals and PWM (1-10kHz) digital inputs for stepless speed regulation, while the FG tachometer output delivers real-time RPM feedback for closed-loop integration with PLCs, microcontrollers, and building automation platforms. Built-in protection features include soft-start, current limiting, locked-rotor protection, and reverse polarity protection. The fan construction features a die-cast aluminum housing with IP44-rated sealing, ball bearings for any mounting orientation, and Class B insulation for safe operation to 130°C ambient. Rated for 50,000 hours L10 lifespan at 40°C with minimal maintenance, this fan is the optimal choice for high-airflow low-voltage DC ventilation applications where moving the maximum volume of air is the primary requirement.

DC Backward Centrifugal Fan
Type	FB3G250-24GL-91
Model	BLDC92

Remarks:

I. Standard lead wire length is 300mm; customized length available upon request.

II. Control via 0-10VDC analog signal or PWM digital signal.

Test condition:

I. Measurement performed according to ISO 5801, using double chamber method.

II. Test voltage: 24VDC, ambient temperature: 23±2°C, relative humidity: 50±10%.

III. Noise measured at 1m distance in anechoic chamber per ISO 3744.

IV. PQ curve shows performance across 0-100% duty cycle at rated voltage.

I. When taking out the fan, do not directly lift the fan lead wire. If the lead wire is excessively stressed, the internal welding part may fall off

II. Do not plug or unplug the fan lead plug when the fan is running

III. If the fan does not work after starting, do not touch the impeller, rotor, or other parts, professional technical personnel are required to inspect the fan to prevent sudden start of the fan from causing hand or other personal injury

IV. Because of the soft start characteristics of the fan, to prevent personal injury, do not touch the impeller or other parts of the fan during powered on or running at low speeds

V. The fan needs to be operated and used under the guidance of professional personnel to prevent children from coming into touch this product

VI. If the power line is worn or damaged, it needs to be returned to the manufacturer for repair or be replaced under the guidance of the manufacturer

VII. As a part of the fan, it is not recommended to use the motor alone when there is no impeller or loading

1. Maximum Airflow in 250mm Series: The FB3G250-24GL-91 achieves an outstanding 1716 m³/h at 605 Pa on only 24VDC — the highest airflow rating among all 250mm DC backward curved centrifugal fans in the FANOVA lineup. This makes it the ideal single-fan solution for high-volume air displacement applications.

2. High-Volume Aerodynamic Efficiency: 75-80% aerodynamic efficiency at 2750 RPM through optimized backward curved impeller geometry, delivering 1716 m³/h from just 150W — moving 11.4 m³/h per watt — achieving 30-40% energy savings over equivalent AC fans.

3. Wide Application Range: Ideal for data center rack cooling, telecom shelter ventilation, solar-powered greenhouse air circulation, battery storage enclosure thermal management, and industrial cabinet cooling. Available for OEM/ODM customization.

4. Sustainable & Durable: EC brushless motor reduces energy consumption by 30%+ versus AC. Die-cast aluminum IP44 housing, ball bearings, 50,000-hour L10 lifespan at 40°C, and 3-year warranty ensure minimal total cost of ownership.

5. Seamless Integration: 0-10VDC/PWM control plus FG tach feedback for PLC/BMS integration. Standard 250mm flange, any-orientation mounting, and maintenance-free BLDC motor simplify installation and eliminate ongoing service.

Q1: What kind of payments do you support?

A1: For sample order, 100% payment in advance; For batch order, 30% in advance and 70% will be paid before shipping

Q2: Will you provide samples?

A2: Sample is available and can be delivered within 7 days for standard models

Q3: How can I choose a more suitable model?

A3: We need the information like fan type, quantity, size, material, voltage, air flow and static pressure.

Q4: How can I place the order?

A4: Usually quote you within 24 hours after we get your inquiry. First sign the PI, pay deposit, then we will arrange the production. After finished production need you pay balance. Finally we will ship the Goods.

Q5: About transportation

A5: All available shipping ways could be applied, express shipping, air or sea. Appointed shipping company or our own forwarders all could be used in shipment. Full-way tracking the cargos for you before the goods arrive.

Q6: How long is the warranty period?

A6: We currently offer 3-year quality guarantee for our own products, and in response to current product problems, our company provides line support, and some customers have been able to improve their products.