Nokia Alcatel-Lucent 3FE66546AA EMA-BFAN-H Fan Module – Detailed Specification

The Nokia Alcatel-Lucent 3FE66546AA, also known as the EMA-BFAN-H, is a high-capacity, intelligent fan module designed for use in carrier-grade telecom chassis, including the 7750 SR and 7450 ESS platforms. This module ensures reliable thermal management by providing forced-air cooling to dissipate heat generated by high-density line cards and processors, thereby maintaining optimal operating temperatures for system stability and longevity.

The fan module incorporates two independent, high-pressure rotors with backward-curved blades, optimized for high static pressure to overcome the impedance of densely packed chassis. Each rotor is driven by a brushless DC motor with built-in Hall-effect sensors for precise speed feedback and commutation. The combination of dual fans provides N+1 redundancy – if one rotor fails, the other can sustain sufficient airflow to keep the system operational until a replacement is installed.

Speed control is dynamic and intelligent. The module includes an internal temperature sensor and communicates with the chassis management system via I²C or PMBus. Based on temperature readings from multiple sensors across the chassis, the fan speed is adjusted in real-time to balance cooling performance and acoustic noise. The default operating speeds range from 3,000 RPM (silent mode) to 12,000 RPM (full cooling mode), with automatic transition triggered by temperature thresholds.

Mechanical design features a rugged metal housing with a quick-release latch for easy insertion and extraction. The module is hot-swappable, allowing replacement without powering down the chassis. It includes a front bezel with a status LED indicating power, operation, and fault conditions. Airflow direction is front-to-back (or back-to-front, depending on chassis design), and the module is keyed to prevent incorrect installation.

Electrical specifications include a nominal input of 12 VDC, with a maximum current draw of 3.0 A per rotor, totaling 36 W typical at full speed. The module includes over-current and over-voltage protection, as well as locked-rotor detection that triggers an alarm and auto-restart after a cool-down period.

Acoustic performance is carefully managed. At low speed, the noise level is below 45 dBA, making it suitable for office environments. At full speed, it may reach 65 dBA, typical for central office scenarios. The module includes vibration dampeners to reduce transmission to the chassis.

Reliability is a primary focus. Each rotor is rated for a minimum of 80,000 hours of continuous operation at 40°C ambient, using dual-ball bearings with high-temperature grease. The module is tested to withstand vibration and shock per GR-63-CORE, and meets NEBS Level 3 requirements.

Management and monitoring are fully integrated. The chassis management system reads speed, current, and temperature values from the module, and can generate alarms for fan failure, speed deviation, or overheating. Historical logs of fan performance are maintained for trend analysis.

Compliance includes CE, UL, and RoHS. The module is designed for use in both AC and DC powered systems, with universal input voltage tolerance.

Typical deployment is in high-density routers, switches, and packet transport systems where heat dissipation is critical. The 3FE66546AA ensures that system components remain within safe temperature ranges, thereby maximizing hardware lifespan and reducing unplanned downtime.

In summary, the Nokia Alcatel-Lucent 3FE66546AA EMA-BFAN-H fan module is a reliable, intelligent, and easily replaceable cooling solution that meets the rigorous demands of modern telecom infrastructure, providing peace of mind for network operators.