ebm-papst motor FAQs1. What different types of motors are there?
What is a 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.
What is a 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.
What is a 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.
What is an 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, 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. 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. 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.
Yes, in two planes while running.
The system operating point is the point of operation of the air mover on its air performance curve. It is described by an airflow and static pressure point. The operating point is that point on the air mover performance curve where the system resistance curve crosses the air performance curve.
System Impedance is the resistance to air flow when moving air through an airflow system. Examples: air filters, air grilles and abrupt changes in flow direction.
Fan laws are a family of mathematical relationships that allows the calculation of new operating characteristics from known system conditions.
Motor insulation systems are the materials used for wire and coil insulation and are classified according to the highest temperature at which normal service life can be expected. There are five motor temperature classifications: A (1050 C), E (1200 C), B (1300 C), F (1550 C) and H (1800 C). The maximum temperature rating is based on the temperature rise of the coil winding plus the ambient air temperature at the motor.
Fifteen (15) feet. You must use a twisted pair of 24 gage wire.
Fan performance sensor.
Red is plus, black is ground, NTC resistor goes between green and ground.
Value-added. This is when ebm customizes an air mover by adding terminals, threaded inserts, sheet metal, etc., to aide in ease of assembly for the end user/customer.
Yes, however, not all speed controls are designed the same, so check with our application engineers to insure trouble-free operation.
Yes. Most crossflow blowers can have the motor rotated in increments of 900. Motor rotation, if required, should be performed at ebm Industries as a value-added service.
Yes. Most models are UL and cUL recognized or CSA certified for use in the US and Canada. Please check with an ebm-papst applications engineer for questions about the approval status of specific models.
In general, seventy-five (75%) percent of the rated voltage of the blower motor is required to reliably start the motor.
Example: Minimum starting voltage: 111 x .75 = 86V
7/16" air gap, otherwise electrical performance of motor will be adversely affected.
Yes. ebm (mvl) products have a three or four digit number on the lower right corner of the label on the blower housing.
029 = week 2, 1999
4999 = week 49, 1999
0500 = week 5, 2000
No. Unless the motor is specifically designed to operate at both 50/60 Hz, each motor must be evaluated for the application on a case-by-case basis.
Yes, many models are available that are manufactured to European standards with equivalent air delivery. 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.
A motor is a device that converts electrical energy into mechanical energy. A motor can operate on direct current (DC) or alternating current (AC) voltage supply, not both.
The single phase AC induction motor is a common design for fractional and subfractional motors. The motor consists of two basic electrical assemblies: the stator and the rotor. The stator is the primary electrical circuit that induces a current in the secondary electrical circuit, the rotor. The combined electromagnetic effect of the two circuits produces rotation of the rotor.
There are two types of single phase AC induction motors commonly used for direct fan applications: shaded-pole and permanent split capacitor.
Shaded-pole motors are simple in construction and the least expensive for subfractional and fractional horsepower applications. The motors typically operate within an efficiency range of 20% to 40%. The components that make up a shaded-pole motor are the stator, the main winding (coil winding), the auxiliary winding (shading coil) and the rotor.
Permanent split capacitor motors (PSC) motors, like all capacitor motors, require an external capacitor to be connected to the motor circuit. The motor typically operates within an efficiency range of 60% to 70%. The components that make up a permanent split capacitor motor are the stator, the main winding, the auxiliary winding, the capacitor, and the rotor.
Induction motors are either asynchronous or synchronous speed motors by design. Synchronous motors operate at a constant speed with or without a load applied to the shaft. Asynchronous motors operate at a variety of speeds and are greatly affected by the load applied to the shaft.
A synchronous speed induction motor will operate at 3600 rpm for a 2-pole motor, 1800 rpm for a 4-pole motor and 1200 rpm for a 6-pole motor using 60 Hz input power.
An asynchronous speed induction motor will operate at significantly lower speeds compared to synchronous motors with the same number of poles.
The speed of an AC induction motor can be changed by a number of methods. In addition to changing the design of a motor, common approaches to speed control are changing the applied voltage or changing the applied frequency.
A reduction in motor voltage can be accomplished with a resistor, variable speed AC transformer, or a solid state speed control.
This technique is not commonly used for ebm’s products.
A brushless DC motor is a DC motor that has commutation accomplished by electronic circuitry instead of brushes. Since there are no brushes to wear out, the brushless DC motor has a life span equal to or greater than an AC motor.
A backward curved impeller (BCI) is a centrifugal air moving device (wheel) with blades inclined in the direction opposite the direction of rotation. Such impellers can work without the aide of a specially designed scroll housing.
Yes, ebm manufactures a variety of fans, blowers, and motors built with materials that offer moisture and corrosion protection: plastics, coated steels, and aluminum or stainless steel alloys are used for scroll housings, impellers, and fan shafts. Moisture protected motors are built to an Internal Protection Classification of either IP44 or IP54.
The air moving industry typically rates fan life using two terms: L10 life of the bearing and MTBF 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 fan life test data 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) 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. However, because mechanical or electromechanical components like bearing and motors do not have constant failure rates over time, this would not be a valid calculation
ebm has fans that can be controlled by a thermistor (a device that changes resistance as temperature changes).
The vertical axis (Y axis) is pressure (inches water or pascals). The horizontal axis (X axis) is flow (CFM or M3H). The curve displays the fan delivery characteristics of specific pressure/flow points.
Fans with sleeve bearings generally need to be mounted with the shaft horizontal. Exceptions can be discussed with our engineering staff. Ball bearing fans can mount in any orientation.
IP rating is an international standard for rating motors for the effects of dust.
Check the ebm-papst catalog for such information.
This is a term to describe the air flow direction moving through a fan related to a common point, the fan motor supports or struts.
An external motor is a motor designed with the rotor on the outside, common construction for brushless DC motors.
The maximum voltage applied is dependent upon the product and application. Consult ebm application engineer for assistance.
A voltage range is the maximum and minimum voltage that can be applied to an air mover where it will operate reliably.
The pressure developed by an air moving device will change proportionally with the air density if the RPM is kept constant. An air moving device powered by an electric motor will change RPM with a change in altitude due to the change in density (less load at higher altitude). This RPM change generally will compensate for altitude changes. The exception is for AC motors that are designed to run very close to synchronous speed at sea level. These will not change the speed with altitude change and will therefore produce less pressure at high altitudes.
Our products are used in various industries and applications: Ventilation, air-conditioning and refrigeration technology, clean room technology, automotive and rail technology, medical and laboratory technology, electronics, computer and office technology, telecommunications, household appliances, heating machines and plants drive engineering.
Our products are not designed for use in the aviation and aerospace industry!