Fans are a critical systematic component of the cooling system, particularly in applications such as supermarket refrigeration, HVAC and telecommunications cabinets. Electronic Commutation (EC) motors change the game for many designers because they allow fans to operate at accurate speeds, unlike alternating current (AC) motors, which must operate at full speed even in applications that do not require cooling.g.
Operating the fan at the proper speed means less energy consumption, less noise and less stress on the components than shrouded pole motors and permanent split capacitor (PSC) motors. For many years, these two motors have been the mainstream choice in fan and fan applications. The motor is simply used to turn the fan, which causes the necessary air flow to cool the refrigeration unit and electronics.
Shrouded pole motors waste a lot of energy in the form of thermal energy and operate at a fixed speed determined by the frequency of the power supply. The performance of the PSC motor is improved, but its efficiency still reaches a peak near full speed.
The EC motor converts the AC voltage to the DC voltage and allows the fan to operate efficiently with the proper conversion. This allows designers to use smaller power supplies, reduce operating costs and meet modern energy efficiency standards.
EC motors combine brushless DC motors with integrated electronics for greater efficiency, precise speed control and greater flexibility. The electronic commutation mechanism controls the current in the motor winding in a controlled sequence, which is ideal for digital and electronic control applications.
Fast application of EC fans
For many years, given the cost of electronics and magnets, it has been difficult to justify the increased material cost of investing in EC motors when a simple shrouded or PSC motor can do the job. With power electronics becoming cheaper and cheaper, and energy costs escalating, EC has been increasingly used in advanced HVAC systems and other equipment requiring variable speed and quiet operation.
With EC motors, the fan speed can be increased or decreased depending on temperature, pressure or network signals. This results in longer bearing life, milder starting currents and longer maintenance intervals. In addition, one fan model can be used for multiple SKUs. With this in mind, fan manufacturers integrate EC technology into complete components that can easily adapt to existing designs.
EC fans are now standard for many new commercial refrigeration equipment, HVAC blowers, and telecommunications racks. In North America, more than half of the new commercial HVAC systems are equipped with EC motors, and supermarket refrigeration equipment is transformed to quickly recover costs due to energy conservation. Of course, AC motors are not silent and are often indispensable in low cost, fixed speed applications where part load efficiency is not important.
Replacement of old equipment with exm-papst ready for use AxiACi
As an early innovator combining DC brushless motors with compact, efficient fan designs, ebm-papst has been the driver of EC motor technology for fans and blowers. The company's wind turbines integrate motors, control electronics and aerodynamically optimized impellers in one package for silent operation, precise speed control and significant energy savings.
The company's AxiACi series of fans (Figure 1) was designed to replace conventional AC fans, providing designers with a viable way to upgrade cooling applications without major modifications to achieve energy efficiency improvements and modern performance.g.
Figure 1: AXACi fans use EC motors to replace older AC solutions. Picture source: EBM-PAPST)
The AxiACi unit combines rugged and wide range of environmental adaptability, operating in the temperature range of - 40 ° C to+75 ° C. These units are worldwide suitable for connecting 90 VAC to 264 VAC (50/60 Hz) inputs, and use three-phase multipolar motors to reduce structural noise.
With a lifetime of 65000 hours, the ebm-fan is the best alternative to older solutions. This fan uses an efficient GreenTech EC motor and an EC-class efficiency AC package, filling the gap between conventional AC fans and full-electronic commutation solutions.
The AxiACi120 model (e.g., 8315100190) is a reliable replacement for older AC fans in cabinet cooling, industrial ventilation, or refrigeration applications. Tubular axial design size 119 mm x 119 mm x 38 mm provides approximately 101 CFM air flow when operating on 115/230 VAC common power. With a dust and water resistance rating of IP65, the product operates in extreme ambient temperatures from - 40 ° C to+70 ° C and is ideal for ready-to-use upgrades.
For designs that require more compact products, AXIACI92U models (e.g., 8315100286) are 92 mm x 92 mm x 38 mm for smaller spaces and applications that require lighter cooling. Although the air flow is relatively gentle, the product provides an incredible static pressure of 0.622 inches HO (155 Pa) allowing air to pass through restrictive filters, grilles, or downstream piping.