FAQ

ebm‑papst offers 4 different types of motors: shaded-pole, permanent split capacitor, brushless DC and EC motors. The various motors are explained below.

Shaded-pole motor
Shaded-pole motors are the simplest AC single phase induction motors and hence the least expensive. Motors of this type have a simple, sturdy design; they are self-starting and require no maintenance; however, they have the lowest efficiency of all motor types - in the range of 20 to 40%. Since starting torque and efficiency are very low, these motors are only suitable for very low power applications.

Permanent split capacitor motor
Permanent split capacitor motors (also known as a capacitor-run motors or PSC) use an externally connected, high voltage, non-polarized capacitor to generate an electrical phase shift between the run and start windings. The motor typically operates with an efficiency range of 60% to 70%. PSC motors are one of the most common AC motors due to their combination of low cost and medium efficiency; however, they are often being passed over for high efficiency DC and EC motors.

Brushless DC motor
A brushless DC motor is a DC motor whose commutation (electrical switching) is accomplished by electronic circuitry instead of metal brushes. Hall sensors in the motor detect the precise rotor location at all times which allows precise timing of the commutation, lower heat rise, and higher efficiency – typically over 90%. Since there are no brushes to wear out and the motors run more efficiently, brushless DC motors are more reliable and have a longer life span than AC motors in similar size ranges. The integrated electronics also allow interface options such as tachometer and alarm output, PWM and/or analog speed control, and additional motor protections such as locked rotor and reverse polarity protection.

EC motor
EC or Electronically Commutated motors are motors in which commutation is accomplished by electronic circuitry, much like DC motors. The main benefit to this is the ability to speed control the motors without the loss in efficiency you see when speed controlling AC motors. The higher efficiency equates to operational energy savings. They also include integrated electronics which are connected directly to AC mains supply and convert the AC input power to DC so no external electronics are necessary. As with all ebm‑papst motors, commutation is brushless and requires no maintenance. EC motors also generate less heat than comparable AC motors which equates to longer service life and higher reliability. Similar to DC motors, EC motors with integrated electronics allow interface options such as tachometer and alarm output, PWM and/or analog speed control, as well as additional motor features and protections such as Modbus communication and wide voltage and frequency ranges.

As opposed to traditional internal-rotor electric motors which have a rotating shaft surrounded by electromagnetic coils, external rotor motors have electromagnetic coils encased inside a rotating shell. These motors are compact, efficient and less susceptible to overheating than internal-rotor motors.

The image below shows a sample ebm‑papst external-rotor motor with part of the rotor (black casing) cut away to expose the windings inside.

This information can be found in the fan’s Data Sheet and Operating Instructions (https://www.ebmpapst.com/us/en/support/downloads/operating-instructions.html), and is printed on the label of the fan itself.

What’s the maximum voltage you can apply to a blower?
The maximum voltage that can be applied to a fan motor varies from model to model, but is typically 5%-10% above the nominal voltage listed. Consult the factory to determine the maximum voltage for a particular part number, and to learn more about the negative effects that high voltages might have on the motor

What is a fan’s of voltage range?
ebm‑papst EC fans are able to perform equally well across a range of input voltages. These fans will have the maximum and minimum acceptable voltages listed on the label, such as the one below:

Note that in order to reach a desired performance point, the fan may need to draw additional current at low voltages.

Can all 60 Hz blower motors operate on a frequency of 50 Hz?
Not all ebm‑papst fans are designed to operate at both 50 and 60 Hz. If a fan is able to accept both 50 Hz and 60 Hz power supplies, it will have a “50/60Hz” mark on its label, such as the one below:

Consult the factory if you intend to use a power supply with a frequency that does not match the recommended frequency of your fan.

When determining fan performance, several factors are taken into consideration. These factors primarily include: airflow, static pressure, operating points, RPM, power & current, and sound performance. Of these factors, ebm‑papst presents a performance curve with our products to provide a quick-glance overview of the performance. Performance curves use just three of the aforementioned factors: airflow, static pressure, and operating points.

What is Airflow?
For the air-moving industry, it is important to know how quickly some volume of air is being displaced from one location to another, or, more simply stated, how much air is being moved in a set amount of time.

ebm‑papst typically expresses airflow in Cubic Feet per Minute (CFM) or cubic meters per hour (m³/h).

What is Static Pressure?
Once again the air-moving industry is faced with another challenge, the resistance to flow. Static pressure, sometimes referred to as back pressure or system resistance, is a continuous force on the air (or gas) due to the resistance to flow. These resistances to flow can come from sources such as static air, turbulence and impedances within the system like filters or grills. A higher static pressure will cause a lower airflow, in the same way that a smaller pipe reduces the amount of water that can flow through it.

ebm‑papst typically expresses static pressure in inches water gauge (in. W.G.) or Pascals (Pa).

What is the System Operating Point?
For any fan we can determine how much air it is able to move in a given amount of time (airflow) and how much static pressure it can overcome. For any given system, we can determine the amount of static pressure it will create at any given airflow.

Taking these known values for airflow and static pressure, we can plot them on a two-dimensional chart. The operating point is the point at which the fan performance curve and the system resistance curve intersect. In real terms, it is the amount of airflow a given fan can move through a given system.

How do I read an air performance curve?
To aid in fan selection, ebm‑papst provides an air performance graph with its products. The air performance graph consists of a series of curves that chart airflow against static pressure.

Follow along on the chart below. The x-axis is for airflow, while the y-axis is for static pressure. The blue line ‘A’ illustrates the fan’s performance outside of a system. To find the operating point 900CFM @ 2 in.w.g., follow the x-axis to 900, then follow the y-axis up to 2 (Point ‘B’). Since this operating point ‘B’ is below the performance curve, it is a point that the fan can achieve.

Lines ‘C’, ‘D’, and ‘E’ are example system resistance curves – as airflow increases, the static pressure (or resistance to airflow) also increases, making it harder to move air. Typically, any point between the highest and lowest of our example resistance curves is the ideal operating range for the fan to achieve its highest efficiency. Some performance graphs will have multiple airflow curves; this would indicate that the fan is capable of multiple speeds in order to match operating points below its maximum speed, thus saving energy.

Fan laws (also known as Fan Affinity Laws or Hooke’s Laws) are a set of mathematical equations used to calculate theoretical operating characteristics (airflow, pressure, and power) at various speeds from measured data of an airmover of similar geometric size.

First Law
The first fan law relates volumetric airflow and rotational speed. The equation below shows us that the volume of airflow (Q) is directly proportional to the rotational speed (revolutions per unit of time, n).

Second Fan Law
The second law relates pressure to rotational speed. The equation below shows us that pressure (lowercase p) is proportional to the square ratio of rotational speed, n.

Third Fan Law
The third law relates power to rotational speed. The equation below shows us that power (uppercase P) is proportional to the cube ratio of rotational speed, n.

Axial fan airflow direction is given as follows:

Single and dual inlet centrifugal blowers with forward curved blades:

Centrifugal fans with backward curved blades:

For a given composition and temperature, air density varies in direct proportion to air pressure. This is related to gravitational attraction between the earth and air molecules being greater for those molecules nearer to earth than those further away. At higher altitudes air density is lower which results in decreased aerodynamic performance.

For example:
A fan operating at 1000 meters over sea level will perform in a different way to a fan operating under the same conditions at 2000 meters over sea level. Using a 500 mm axial fan performance curve as an example, operating at constant conditions (temperature & humidity) but at different elevations the performance curve will behave as follows:

This behavior of course will depend also on the type of fan. Fan performance is affected by the air density. How the air density affects the performance depends on what kind of fan is affected.

For speed controlled fans (EC fans with speed control), a reduction in air density results in the following changes:

Air flow stays constant
Pressure is proportional to air density
Mass flow is proportional to air density
Power input is proportional to air density

(The constant air flow volume is due to the fact that the resistance characteristics of the application also change equally to the reduction of pressure increase of the fan)

Chart explaining fan and blower performance

While for Fans with AC motors and uncontrolled EC motors (n ≠ const.), following is the case:

Reducing air density also reduces the load on the motor.

How much speed is gained by this depends on the motor characteristics.

This results in a new, different duty point of the fan / application.

For altitudes over 2300 meters over sea level the operability of the fans needs to be checked individually. If such approval is requested, further details like clearance & creepage distances with corresponding altitude correction factors, level of pollution, insulation materials, operating conditions, ambient temperatures and nominal supply voltage may be necessary.

ebm‑papst recommends using EC motors when speed control is required. EC motors provide no loss of efficiency at lower speeds while also avoiding the annoying motor hum of reduced-speed AC motors. If speed control is required with an AC motor, there are several possible methods:

1. Series resistance:

Provides fixed speed steps by reducing the motor voltage.
Cost efficient, but can only handle small currents with readily available resistors.
High losses and increased heat loads can occur

Diagram of series resistance with EC motors

2. Series capacitance

Provides fixed speed steps by altering the motor power factor.
Cost efficient, although more expensive than resistors.
Can handle higher currents than resistors.
Lower losses and decreased heat rise as compared to resistors.
MUST still use any required run-capacitors.

3. Transformer

Provides fixed speed steps by reducing the motor voltage.
Can handle more current than typical series resistors.
Typically easy to source from third party suppliers.

4. Phase-angle control

Continuous speed setting for 1~ motors possible via change in motor voltage
Cost-efficient control method
Acoustic performance may deteriorate – an audible hum is probable at low speeds.
Temperature rise may increase and must be tested in the final application

Diagram of phase angle control with EC motors

5. Frequency inverter with all-pole sine filter (VFD)

Continuous speed setting for 3~ motors via change in motor frequency.
High efficiencies are possible with well-matched VFD and motor systems.
The matching of the VFD and motor must be done by the end user; however.
Most expensive AC speed control solution
An all-pole sine filter (phase-to-phase and phase-to-earth) must be used to avoid bearing and insulation damage.

Diagram of frequency inverter with EC motors

ebm‑papst offers multiple options for speed control on EC and DC motors, including PWM, analog signal (0-10Vdc or 4-20mA), open- or closed-loop sensor control, and Modbus. Available options vary by fan part number; please consult the part-specific fan data sheets for details on which types are included on specific parts.

Analog Input and Open-Loop Sensor Controls
Almost all ebm‑papst EC fans can be speed controlled via an analog signal, such as 0-10Vdc voltage or 4-20mA current. Speed is typically proportional to the input signal (with 0Vdc/4mA corresponding to 0rpm and 10Vdc/20mA corresponding to full speed). However, this can vary by part number and for some fans can be parameterized by the customer (see section “Modbus” below for more details). Please consult the fan-specific data sheet or the OEM as appropriate for details on the relationship between speed and input control signal for a given part number.

Some ebm‑papst fans also include a 10Vdc output signal in addition to a 0-10Vdc input, allowing a potentiometer, thermistor, or other sensor to be wired directly into the fan without an external voltage source or power supply. These sensors can then provide feedback through the analog signal to provide the same open-loop control as above. It is considered “open-loop,” because in this simple configuration, the fan doesn’t check its speed – it simply runs at the speed indicated by the signal.

PWM
Pulse-width modulation (PWM) is a common speed-control method which uses a pulsed voltage signal which switches between high and low voltage at high frequency (typically in the range of 1-10kHz for ebm‑papst fans). The duration of the “high” signal relative to the duration of the “low” signal determines the speed of the fan. So, if for one high/low cycle the signal is “high” for 50% of the cycle and “low” for the other 50%, this represents a 50% PWM signal; 75% high and 25% low would be 75% PWM, and so on.

The acceptable voltage and frequency range of the PWM signal varies by fan, as does the relationship between PWM percentage and fan speed. The part-specific data sheet should always be consulted.

PLEASE NOTE, it is not recommended to use a pulse-width modulated SUPPLY voltage on any ebm‑papst fans; PWM should only be used on a dedicated PWM control input wire. Many of our fans use internal microcontrollers that are not rated for a pulsed voltage and may be damaged by it, causing premature fan failure.

Modbus
Many of ebm‑papst’s larger fans have a Modbus interface built in. This allows the OEM and end-user to change many parameters of the fan control. The simplest use is to simply tell the fan what speed to run, and monitor the fan outputs (speed, internal temperature, power, voltage, current, etc). The controls permitted can get much more complicated, though, allowing for de-icing features, custom speed curves, failsafe speed settings, and much more.

For a more detailed analysis of possible options, you can download our free Modbus software (EC Control) and Application Guide from our website here: https://www.ebmpapst.com/us/en/support/downloads/software/ec-control.html

You can also find approved 3^rd party Modbus control manufacturers here: https://www.ebmpapst.com/de/en/products/control-electronics/approved-controllers.html

Closed-Loop Sensor Control
Our largest EC fans even have built in proportional–integral–derivative controllers (PID). This permits closed-loop sensor control, via any sensor that can provide a 0-10VDC, PWM, or 4-20mA signal. Using our EC Control (see section “Modbus”, above), the exact parameters can set uniquely for each application. The fan can be programmed with the sensor’s unit and range as well as a set point, and provide continuous control based on the set point. It is considered “closed-loop” because the fan not only responds to the sensor signal, but also checks this sensor signal continuously to ensure it is getting closer to the set point. If it is not, the fan adjusts speed accordingly. This provides a closed feedback loop to ensure the fan is always running at the optimum speed setting.

Supply Voltage Control (DC-only)
ebm‑papst compact DC fans can achieve a limited level of speed control by modulating the supply input voltage over the rated voltage range. For example, a nominal 24Vdc fan with an acceptable voltage range of 16..28Vdc will run slower at 16Vdc and faster at 28Vdc. The achievable speed control range will not be as wide as with fans with dedicated speed control circuits (such as a 0-10Vdc input), and is typically in the range of 70-110% of nominal speed.

Forward Curved Impellers

There are two types of forward curved impellers, dual and single inlet.
Used primarily in medium pressure, high flow applications.
Possible market uses: ventilation, refrigeration etc.
https://www.ebmpapst.com/us/en/campaigns/product-campaigns/centrifugal-fans/centrifugal-fans-with-forward-curved-blades.html

Backward Curved Impellers

Used primarily in high pressure, high flow applications.
Possible market uses: data center, general ventilation, agriculture; transportation etc.
https://www.ebmpapst.com/us/en/products/centrifugal-fans.html

Axial Fans

Used primarily in low pressure, high flow applications.
Possible market uses: LED, ventilation, agriculture; transportation, etc.
http://www.ebmpapst.us/en/products/axial_fans/axial_fans.php

Tangential Blowers

Image of Tangential dual and single blowers

Used primarily in low pressure with laminar flow.
Possible market uses; fire place inserts, etc.
https://www.ebmpapst.com/us/en/products/tangential-blowers.html

The above designs are also available in compact sizes.

Possible market uses: IT, medical, etc.
http://www.ebmpapst.us/en/products/compact_fans/compact_fans.html

ebm‑papst does not sell individual replacement parts. The fans and blowers are sold as a whole unit. ebm‑papst also does not recommend anyone attempt to fix the product on their own.

You can check distributor stock on our website here: https://www.ebmpapst.com/us/en/support/distributors.html

We do offer limited explosion protected fans approved to ATEX standards. ebm‑papst Ex Protected fans are NOT UL APPROVED. Please contact an ebm‑papst application engineer for application related details.

Click the link below for general information about EX Protected fans.
https://www.ebmpapst.com/us/en/campaigns/industry-campaigns/ex-atex.html

Yes, ebm‑papst fans are dynamically balanced in two planes, per the standard DIN ISO1940. We typically balance to grade G6.3; however, other balancing grades may be available upon request.

ebm‑papst fans are designed and produced as a complete assembly. This means that the impeller, rotor, and stator are designed and balanced to provide a complete, stable product. Systems where the motor and fan blade are balanced separately can result in a system that is imbalanced if the two component’s tolerances are aligned.

Yes. Date code structure may vary depending upon production location but is typically in a WWYY (week, week, year, year) format. Some may or may not have a “.” or “/”, i.e. ww.yy or ww/yy.

Image of example of date code WWYY format

Example of Date Code in "WWYY" format.

Example of Date Code in "WW/YY" format.

Example of Date Code in "WW.YY" format.

ebm‑papst compact fans have life expectancy listed in L10 operating hours on the respective catalog page. Larger fans typically have a minimum expected L10 operating life of 40,000 hours; however, a more exact (and usually much larger) estimate can be made upon request.

The air moving industry defines fan life using two terms: L10 which is life of the bearing and MTBF which is life of the electronic components.

L10
Life is defined as the number of hours after which 10% of the fans in operation would be expected to experience bearing failure. This number is obtained using data from thousands of fan life tests and Weibull-function statistical analysis to obtain a failure distribution prediction. Bearings usually fail because of lubricant degradation over time, which is greatly affected by the ambient temperature in which the fan is operating. This is why bearing L10 life numbers are always provided at a specific ambient temperature.

MTBF (Mean Time Between Failures)
MTBF predications are based on assumed constant failure rates over the useful lifetime of electronic components like resistors, capacitors and semi-conductors. These predictions are usually based on MIL-HDBK-217 or Bellcore TR-332. Sometimes requests are made for the MTBF of the complete air mover assembly.

As mechanical or electromechanical components like bearing and motors do not have constant failure rates over time, MTBF would not the best calculation to use. ebm‑papst uses the L10 calculation for fans and blowers because it better matches the real life results – few failures early and an increasing number of failures as the bearing lubricant ages.

General Mounting Orientation

Check spec sheet and operating instructions for appropriate mounting orientation. If the spec sheet and operating instructions are not available on the website, please contact ebm‑papst Inc.

Spec Sheets:
https://www.ebmpapst.com/us/en/support/downloads/datasheets.html

Operating Instructions:
https://www.ebmpapst.com/us/en/support/downloads/operating-instructions.html

Contact for additional questions regarding mounting a blower:
https://www.ebmpapst.com/us/en/support/contact.html

Additional Installation Guidelines (Axial Fan – Fan only)

We highly suggest using an ebm‑papst designed wall ring for maximum efficiency and lowest sound characteristics.

An ebm‑papst designed wall ring will help air performance and efficiency of the fan when compared to an aperture.

Example of using a wall ring to mount an ebmpapst fan

Axial Fan – with wall ring

Obstructions on the inlet and exhaust side will negatively affect the performance of the fan.

Example of obstructions effects when mounting an ebmpapst fan

Backward Curved and Forward Curved Blower – Blower only

The inlet ring position will affect the efficiency and the sound characteristics of the blower.

Inlet rings are available separately from the blower. Part numbers are available in the blower spec sheet.

Example of the inlet ring affecting the efficiency an ebmpapst fan

Example of the inlet ring affecting the efficiency an ebmpapst fan. Effects of nozzle gap dimension

We highly suggest using an ebm‑papst designed module for both backward curved and forward curved blowers for ease of use.

Inlet rings are positioned in the modules for maximum efficiency and sound characteristics.

Backward curved impeller modules hold the impeller at the optimum distance for the inlet ring.
Forward curved impellers require a scroll housing in addition to the inlet ring for optimum performance.

Backward Curved Blower – module mounting

For 3D and Gen I RadiPac impellers, ebm‑papst recommends a hydraulic diameter no less than 1.8 for optimum efficiency.

Illustration of effects of installation space when mounting our product

For Gen II RadiPac (Airfoil) impellers, installation space has less effect on the performance of the blower.

Forward Curved Blower – Module mounting

ebm‑papst has dual and single inlet scroll housings available for forward curved blowers. Obstructions on the inlet side of a dual or single inlet forward curved blower has an effect on the performance of the blower.

illustration of obstructions on the intake side

ebm‑papst fans are commonly used in IT/Telecomm, HVAC, refrigeration, transportation, data center, power conversion, heating, appliance, lighting, and industrial applications. Nearly any application that requires an air moving product can be serviced with an ebm‑papst fan. It may be easier to define what applications ebm‑papst fans cannot be used in:

ebm‑papst fans are not designed for and are not recommended for use in airborne or military applications. Special care should be taken in applications with rigorous standards such as Hazardous Locations, rail transit, outdoor use / exposure, and gas-fired appliances. Contact ebm‑papst for assistance with such applications.

Yes, ebm‑papst manufactures a variety of fans, blowers, and motors built with materials that offer moisture and corrosion protection.

Specific corrosion protection requirements should be discussed with engineering. Depending on the requirements, the housing, impeller or blades, and motor materials can be modified to withstand corrosive environments, including humidity, salinity, acidity, and more.

Moisture protection of the product is indicated by the IP rating:
‘IP’ stands for Ingress Protection and rates the degrees of protection provided against the intrusion of solid objects and water. The IP rating is indicated by ‘IP’ followed by two numbers:

The first digit indicates the level of protection against solid foreign objects.
The second digit indicates the level of protection against ingress of water.

Some of the most common IP ratings for ebm‑papst products are outlined in bold below. Please check the individual product spec sheet to determine the ingress protection rating.

Image of Overview of Stress Criteria for Ingress Protection (IP) Protection Classes

Yes. Most models are UL and cUL recognized or CSA certified for use in the US and Canada. For many products, the motor used within the assembly will be UL recognized and included in the agency file. Other products will have the complete fan assembly included within the agency file. The agency approvals for a specific fan are noted on the corresponding data sheet. Please check with an ebm‑papst applications engineer for questions about the approval status of specific models.

Yes, many models are available that are manufactured to European standards with equivalent air performance. Our EC motors are all 50/60Hz and can be used with either frequency without impact on the air performance. AC models that are not currently designed with European voltages can be supplied with minimum production order quantities. Most models designed for European voltages are built to VDE specifications. All current European models carry the CE mark.