EC fan
Also known as: electronically commutated fan, EC motor
Short definitionA brushless fan with its motor and drive electronics in one housing. It connects straight to the mains, and its speed is set to any value with a 0–10 V signal.
EC stands for electronically commutated. The rotor carries magnets and there are no brushes; the board on top of the motor feeds the windings in turn. The same board rectifies the alternating current, so no separate drive is needed in the panel and the fan runs on a 230 V or 400 V supply. The efficiency gap is clear: a conventional AC motor gives 50–70%, an EC motor reaches 85–90%.
As speed is reduced, consumption falls with the cube of the speed; a fan turning at 60% uses about a fifth of its full-speed power. When the fan inside the room uses less, the cooling load shrinks too. Orders and quotes should state the supply voltage and the signal type. Feeding this fan from a frequency inverter or a phase-cut controller damages its board. The signal cable is not laid in the same duct as power cables.