EC Modular Plug fans feature an EC motor to motorise lightweight and aerodynamically designed backward curved impellers for superior noise attenuation and performance.
External rotor motors are usually contained within the depth of the fan impeller, thus saving the space normally occupied by a standard motor. They are located in the air stream, so temperature is limited, and are generally of protection class IP44, so the air needs to be clean and dry to avoid motor contamination. The range of backward curved impeller is available as a free running option or an EC modular plug fans configuration.
EC backward curved centrifugal fans develop pressure within the envelope of the impeller and do not, therefore, rely on a scroll housing for this purpose. They are relatively low cost and can be simply and cheaply housed. Air is drawn through a radius inlet ring, which minimises pressure losses and air leakage, and is discharged at 90° to the inlet axis. The impeller has a ‘non-overloading’ characteristic in that it draws maximum power near the centre of its pressure/volume flow curve.
Low-cost speed control is possible for EC fans by supply voltage variation, either by an electronic (triac) method or by a transformer.
