ebm-papst Fans, Blowers and Technology

by Matt Menard, Market Manager - Air Conditioning

In the world of HVAC, motors move conditioned air throughout the system. When a motor fails, cooling or heating ceases, leaving occupants of that building uncomfortable. The motor can be replaced relatively quickly with an experienced technician. However, diagnosing what caused the failure is difficult, time consuming and often ignored.

Motor failure is a major headache that can cost building owners significant money. With limited budgets and resources, implementing a preventative maintenance program on motors to minimize failures can be difficult for most. So what is the solution?

The December 9 issue of ACHR News discusses causes and prevention of motor failure. All of these types of failure can be avoided by choosing external rotor EC motor technology, such as is utilized in ebm-papst’s product line, to boost reliability and efficiency.

1. Belt — Belt tension is critical in avoiding vibrations between the fan wheel and motor. Belts tend to stretch throughout their lifetime, so technicians tend to over tighten during replacement. A belt that is too tight overloads the motor and shortens the lifespan. ebm-papst external rotor motors do not use belts—the fan wheel is mounted directly to the motor rotor.

2. Overheating — This is the most common cause of failure. Dirt buildup on the fan wheel and poorly designed/installed ductwork causes additional strain on the motor resulting in overheating and a shortened lifespan. ebm-papst EC motors have temperature sensors built into the internal electronics package that act as a safety device in the case of overheating.

3. Electrical Fluting — When utilizing a Variable Frequency Drive (VFD) for speed control, users can experience a phenomenon called electrical fluting, which basically equates to a mini-lightning storm that occurs within the motor as voltage and frequency are regulated by the VFD. This ‘storm’ affects the bearings, resulting in premature failure. Electrical fluting is unpredictable and requires additional measures such as shaft grounding kits and ceramic bearings to prevent. ebm-papst EC motors have built-in speed control and do not require a VFD, eliminating the electrical fluting issue.

In addition to eliminating belts, adding temperature sensors and built-in speed control, industry experts such as Jim Connell of AirXChange Inc. believes that ECM fans are more reliable and use less energy than traditional AC motors and drives.  Utilizing external rotor EC motor technology provides not only the most reliable, but most efficient technology available.

by Tom Costello, Market Manager – Appliance & Heating Gas

As we sit down to dinner at night, most of us do not give any thought to what’s in our kitchen appliances or how they even work. We take for granted that our refrigerator keeps our food from spoiling, that our oven cooks the food to a perfect temperature, that our range hood removes all the odors and smoke from the room, and that the dishwasher cleans and dries our dishes at the end of the meal. We simply expect our appliances to work to free up our time for other interests!

To help meet that expectation, our R&D engineers are developing air moving solutions that allow your kitchen appliances to work better, longer, and safer. That's right, you may not be aware that each of the kitchen appliances listed above often includes a fan that improves the transfer of heat for cooling, heating, or simply air quality. For example, cooling insures the controls don't overheat in your oven or that the food remains cold enough to last for days or months in your refrigerator or freezer. Conversely, convective heating improves cooking performance in a range or wall oven and also improves the drying performance in your dishwasher.

Our fans are used in all types of kitchen appliances for cold, hot, and wet applications. In addition, now they are being designed to further improve the quality of your life by reducing the electrical energy consumption and, thereby, your "carbon foot print". A good example of this is a recent development program with one of our European appliance customers that manufactures one of the highest rated dishwasher products in the world market. The development was based on a strategic partnership between ebm-papst (supplier) and the appliance OEM (manufacturer) that resulted in both parties achieving their goals to grow sales with a progressive technology that also is environmentally friendly or "Green".

For many years, conventional drying technology would include a radial fan driven by an AC shaded pole motor in combination with a humidity valve and a custom scroll housing to remove the moist hot air from the dishwasher and then cool it to a safe temperature before venting into the kitchen.

Although effective at accelerating the drying process, energy consumption and drying time was still too high; however, recent advancements in motor technology and materials now allows for a new improved drying cycle. ebm-papst is a leader in electronically commutated (EC) motor technology in many markets and now recent  design advances allows us to bring this technology to kitchen appliances. In addition, since we design the impeller and scroll housing too we can optimize airflow, size, and material selection to provide a robust assembly that meets the demand of the application and operates with very low energy consumption.

This progress in air moving technology has now allowed the appliance OEM to introduce a new drying process that can further accelerate the drying time in an environmentally friendly manner. So in the end, advancements in technology applied in an eco-friendly manner result in lower energy consumption and reduced drying time!