The main challenges of the twenty-first century are to reduce energy consumption and environmental Safety. Since 2005, at regular meetings of the G8 leaders, these issues have been highlighted at the level of key global issues. To explore savings opportunities in energy products European countries the same year the EcoDesign directives were approved. Based on these directives, energy consumption in European countries should be reduced by 34 terawatt-hours per year.
Fans and air conditioners are among the leading group of equipment in terms of energy consumption in Europe. The amount of electricity consumption in Europe is this moment is 400 terawatt-hours per year, and by 2020 it can reach 650 terawatt-hours per year. In 2010, the European Parliament adopted strict measures to compulsorily reduce the electricity consumption of fans. Accordingly, everything European manufacturers ventilation equipment when creating their products are forced to take into account new energy efficiency standards.
EC engines are one of the most promising directions in the field of fan production. Already now EC engines found wide application in refrigeration, ventilation equipment, air conditioners, heat pumps. According to preliminary calculations, further application of EC technologies in these industries will reduce electricity consumption in Europe by more than 30%.
EC motors, or electronically commutated permanent magnet motors, are brushless motors DC with external rotor, having a built-in control function and with the ability to directly connect to the network alternating current. Unlike traditional engines, with transformer or electronic adjustment speed, in EC engines optimal and effective work at any speed it is provided by electronic (contactless) switching.
Built-in EC controller allows you to control the fan based on signals external devices (sensors temperature, pressure, humidity, timer, etc.) remotely through a dispatch system.
In addition to significant energy savings, EC fans, due to their low heating, do not require additional cooling, and the costs for them service maintenance minimal.
The presence of full automatic control of the operation of protection against overheating, phase imbalance, rotor blocking, etc. significantly extends the service life of EC equipment compared to traditional ones.
Due to the fact that EC fans have a design in which the engine is located inside the impeller, the possibility of it mechanical damage reduced to a minimum. In addition, this fan design allows for excellent system balancing, maximizing compact size, minimum level noise.
Absence V-belt transmission, pulleys, tensioning mechanisms and other elements of traditional fans minimizes operating costs.
All of the above and maximum opportunity smooth and precise adjustment depending on external conditions without any additional equipment, minimizes the total cost of the system.
EC motors are more reliable in operation during network fluctuations. Unlike usual asynchronous motors, which begin to overheat when the voltage is slightly exceeded, EC motors operate stably at voltages up to 480V, and when the voltage drops to a certain level, the motor produces Emergency Signal and stops smoothly.
Despite the fact that EC fans are quite expensive today, their payback period is short.
Low power consumption:
Achieved through the use of an energy-efficient EC motor with an efficiency above 90%, as well as an improved design of the impeller with reverse-curved blades. Wherein high efficiency ensured over the entire range of operating speeds.
Achieved through the use of an energy-efficient EC motor with an efficiency above 90%, as well as an improved design of the impeller with reverse-curved blades. At the same time, high efficiency is ensured throughout the entire range of operating speeds.
Additional costs for the purchase of a VKPN EC fan are recouped within the first year of operation only due to energy savings.
Built-in speed control:
Allows you to smoothly and most accurately reach the design point of the ventilation network, further reducing energy consumption.
Impeller speed control:
Carried out through electronic unit control located in the blowing zone.
Extended operating range:
This is achieved through the use of a high-pressure wheel of an improved design with an increased zone of maximum efficiency.
Low level noise VKPN EU:
It is significantly quieter than a standard duct fan with forward-curved blades.
Smooth start:
The use of microprocessor control of the EC motor made it possible to incorporate a soft start function into its design by default. Starting current it does not exceed the rated current and, as a result, does not create additional load to the electrical network.
High service life:
Due to the increased power reserve of the EC engine, the absence of sliding elements in it electrical contacts, as well as the use of a lightweight aluminum wheel in the fan, which does not overload the bearings. The increase in power reserve led to a decrease operating temperature EC motor windings up to 45 °C, which, in turn, sharply reduced their wear. The electronic unit is designed to automatically turn off the fan when the current load exceeds the permissible value.
WARRANTY PERIOD - 36 MONTHS
DesignVKPN EC fans:
The fan housing is made of galvanized steel, the connection is on a tire rail. Working wheel The fan is made with backward-curved blades in the right direction of rotation (clockwise when looking at the fan from the suction side).
ApplicationVKPN EC fans:
VKPN EC fans are used in stationary ventilation, air conditioning systems, air heating. They are compact and easy to install in any position, mainly horizontal.
DesignVKPN EC fans:
VKPN ES fans are manufactured according to TU 4861-019-15185548-04.
terms of UseVKPN EC fans:
If there are increased requirements for the nominal values of environmental climatic factors, it is possible to supply fans with the following operating conditions:
placement category 1 with an ambient air temperature of -50 °C to +45 °C, containing solid impurities no more than 10 mg/m3, not containing sticky substances and fibrous materials, in a temperate climate of the 2nd placement category according to GOST 15150-90 ( protected from exposure to precipitation).
Advantages:
- Energy efficient engine
- 100% speed control
- Built-in speed controller
- Built-in motor protection
- Comes with mounting bracket
Design: The body is made of galvanized sheet steel. To increase the tightness of the housing, its parts are rolled. The housing has a minimum flange length of 25 mm for proper attachment to air ducts. A mounting bracket is attached to the housing for quick and easy installation on a wall or ceiling.
Speed regulation: The fan comes with a 0-10V potentiometer connected. The potentiometer has factory setting at a level of 6-10V, which can be changed as necessary.
| Model | Voltage (V) | Power (W) | Weight, kg) | |
| K 160 EC Circular duct fan | 230 | 79.4 | 544 | 3.3 |
| K 200 EC Circular duct fan | 230 | 78.6 | 774 | 3.3 |
| K 250 EC Circular duct fan | 230 | 120 | 1033 | 3.9 |
| K 315 L EC Circular duct fan | 230 | 340 | 1732 | 7.2 |
| K 315 M EC Circular duct fan | 230 | 166 | 1415 | 6 |
KVO EC
| Model | Voltage (V) | Power (W) | Max. air flow (m 3 /h) | Weight, kg) |
| KVO 100 EC Circular duct fan | 230 | 60.4 | 312 | 5.6 |
| KVO 125 EC Circular duct fan | 230 | 111 | 472 | 5.6 |
| KVO 160 EC Circular duct fan | 230 | 116 | 547 | 6 |
| KVO 200 EC Circular duct fan | 230 | 123 | 868 | 10.3 |
| KVO 250 EC Circular duct fan | 230 | 312 | 1501 | 20.4 |
| KVO 315 EC Circular duct fan | 230 | 331 | 1901 | 25.6 |
KVKE EC
Advantages:
- Energy efficient EC motor
- 100% speed control
- Low noise level
- Built-in motor protection
EC technology is an intelligent technology using integral electronic system control to ensure that the engine always operates at optimal load. Compared to AC motors, the energy efficiency of EC motors is much higher.
Design: KVKЕ EC is a single-suction centrifugal fan in a sound-insulated casing. The KVKE EC body is made of galvanized sheet steel with a 50 mm layer of thermal and acoustic insulation made of mineral wool. Internal surfaces protected by perforated galvanized steel plate.
Speed regulation: The fan comes with a 0-10V potentiometer connected, making it easy to find the desired operating point. The potentiometer is factory set at 6-10V, which can be changed as needed.
| Model | Voltage (V) | Power (W) | Max. air flow (m 3 /h) | Weight, kg) |
| KVKE 125 EC Circular duct fan | 230 | 68.7 | 384 | 13.7 |
| KVKE 160 EC Circular duct fan | 230 | 67.8 | 544 | 17 |
| KVKE 200 EC Circular duct fan | 230 | 156 | 864 | 18.8 |
| KVKE 250 EC Circular duct fan | 230 | 265 | 1156 | 28.1 |
| KVKE 315 EC Circular duct fan | 230 | 308 | 1771 | 38.8 |
EU fans used in industry, based on an engine with DC, with built-in electronics, which is powered from a mains voltage with a power of 380 volts. Was developed this type fan in order to reduce energy consumption and increase efficiency, this is a pressing problem nowadays, because electricity consumption is increasing every day.
Advantages of EC fans
1) By optimizing the system, energy costs have been reduced.
2) No maintenance costs.
3) Since the engine practically does not heat up, EC fans practically do not emit heat into the environment.
4) Small fans in size, with sufficiently high power.
5) All electronics that are necessary for control and the filter are built into the engine compartment.
6) The engine is fully coordinated with the electronics.
7) Smooth and precise adjustment is possible, it depends on the temperature and pressure in the system in general.
8) The engine is completely protected from mechanical influences.
9) Electrical loads are not scary.
10) Quick connection.
11) Long service life, which reaches up to 9 years.
12) Good management.
13) Not noisy work at all.
14) A complete inspection of the ventilation system is possible if EC fans are installed, in some cases using the Internet.
In addition to all these advantages, you can control the operation of a fan or an entire group yourself, using a laptop or a regular computer. All this happens using Bluetooth. You can set parameters in which we give a command directly to one fan, and all the others repeat after it, thereby ensuring the operation of the entire group.
To monitor the operation of the fans, as well as their testing, only one operator is enough; he can control all the actions taking place in the ventilation system.
Principle of operation
The rotor magnetic field is formed using permanent magnets. All switching is electronic, so it does not wear out. EU fans connect to constant voltage or using a special module directly to the electrical network.
Description of fans
Electronic centrifugal ventilation units have curved blades and have an impeller diameter that varies from 85 to 450 millimeters. Approximate productivity reaches 11-13 thousand cubic meters per hour. In turn, EC fans, which have curved blades, have diameters from 120 to 630 millimeters, their productivity is greater and reaches 17,500 cubic meters per hour.
All fans have an impeller that is attached to the rotor housing. It turns out that the engine is inside the wheel. Due to this design, the fan retains increased balancing, small size, low noise level, and sufficient long term operation.
Comparison of EC fans with conventional units
When using AC technology, installation work and other equipment costs may increase. Very big noise. Also, with this type it is necessary to use a large amount of power. Regulation conventional fans occurs through the use of frequency conversions, this allows it to be adjusted in a range of only 40%. In turn, EC fans can be controlled in the range of 87-89%.
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Noise level comparison
Benefits of using EC fans
1) Low power consumption.
2) Maintaining the required parameters.
3) Low maintenance costs.
4) There is no need to purchase consumables.
5) Decent size reduction.
6) Reliability in operation
7) When constructing a project, there is absolute flexibility of the system.
8) As noted earlier, very low noise.
Features that EC fans have:
1) If the mains voltage fluctuates, they have greater reliability.
2) A very large operating range from 380 to 480 V. If the voltage drops, the EC fans stop smoothly and an alarm signal appears; in the case of a conventional fan, it simply stops its operation without sending any signals.
3) Reliability is achieved through a built-in protection unit. It allows you to protect the impeller blocking, searches for damaged phases, starts the engine smoothly, and protects the system from overheating and short circuits. This block allows you not to design additional automatic protection.
4) EC fans do not include various pulleys and belts in the ventilation system, which significantly reduce reliability and require maintenance and constant repair.
5) Today, the issue of saving energy remains a pressing issue, so this type of fan is very effective because it consumes a small amount of electricity.
6) EC fans do not require large rooms, as they have fairly compact dimensions.
7) It is possible to change the number of revolutions.
The energy efficiency of equipment largely depends on the energy efficiency of the components and technical solutions used in it. Variable speed motors have recently become popular in compressors, pumps and fans.
Increased efficiency by optimizing the components used
Along with highly efficient induction motors, motors with permanent magnet rotors, which have a high efficiency, are now widely used. Motors using this technology are commonly known in the HVAC industry as Electronically Commutated (EC) motors. Typically, EC motors are used in external rotor fans.
To use EC technology in a variety of industries, Danfoss has improved the proven VVC+ algorithm and optimized it for permanent magnet synchronous motors. The efficiency of this type of motor, often abbreviated as permanent magnet (PM) motors, is comparable to that of EC motors. At the same time, the design of PM motors complies with IEC standards, which allows them to be easily integrated into both new and existing systems and significantly simplifies the commissioning of motors.
Danfoss EC+ technology allows IEC compliant PM motors to be used with Danfoss VLT frequency converters.
Energy efficiency standards
Increasing system efficiency is an easy way to reduce system energy consumption. For this reason, the European Union has approved minimum energy efficiency standards for a number of technical devices. Thus, a minimum energy efficiency standard (MEPS) has been introduced for three-phase induction motors (see table).
Table. MEPS standards for electric motors
However, to achieve maximum energy efficiency, you need to pay attention to the performance of the system as a whole. For example, frequent start/stop cycles on IE2 class motors lead to an increase in energy consumption, which negates the savings achieved in normal operation.
Particular attention must also be paid to fans and pumps. Using a frequency converter in conjunction with devices of this type allows you to achieve higher efficiency. Thus, the determining factor is the overall system performance, not the performance of individual components. In accordance with VDI DIN 6014, the efficiency of a system is defined as the product of the efficiency of its component parts:
System efficiency = converter efficiency × motor efficiency × connection efficiency × fan efficiency.
As an example, consider the efficiency of a centrifugal fan with an external rotor used in conjunction with an EC motor. To achieve a compact system size, the motor is partially located inside the fan impeller. This design reduces fan performance and the efficiency of the system as a whole. Thus, high engine efficiency does not guarantee high efficiency of the entire system (Fig. 1).
Rice. 1. Efficiency of various systems using a centrifugal fan with a diameter of 450 mm. The efficiency of the motors was determined during measurements. Fan efficiency was obtained from manufacturers' catalogs
Operating principle of the EC motor
In the HVAC industry, an EC motor typically refers to a special type of motor that is compact in size and highly efficient. EC motors operate on the principle of electronic commutation instead of the traditional brush commutation found in DC motors. Manufacturers of EC motors replace the rotor windings with permanent magnets. Magnets improve efficiency, and electronic commutation eliminates the problem of mechanical wear on brushes. Since the operating principle of an EC motor is similar to that of a DC motor, such motors are often called brushless direct current (BLDC) motors.
Motors of this class usually have a power of up to several hundred watts. In the HVAC industry, they are most commonly used in the form of external rotary motors and are used in a wide power range. The power of some devices can reach 6 kW.
Thanks to the built-in permanent magnets, permanent magnet motors do not require a separate winding for excitation. However, to operate they require an electronic controller that generates a rotating field. Connecting directly to the power line is usually not possible or results in reduced efficiency. To control the motor, the controller (frequency converter) must be able to determine the current state of the rotor at any time. Two different methods are used for this purpose, one of which uses feedback from the sensor to determine the current position of the rotor, and the other does not.
A distinctive feature of a motor excited by permanent magnets is the nature of the reverse electromotive force (EMF). In generator mode, the engine produces a voltage called back EMF. For optimal motor control, the controller must ensure that the input voltage waveform matches the back EMF waveform as closely as possible. Manufacturers of brushless DC motors use square-wave commutation for this purpose (Fig. 3).
PM motors as an alternative to EC motors
Each type of permanent magnet motor has its own advantages and disadvantages. PM motors with sinusoidal commutation are simpler in structure, but they require a more complex control circuit. In the case of EC motors, the situation is diametrically opposite: creating a square wave of back EMF is a more complex task, but the structure of the control circuit is significantly simplified. However, electronic switching technology is characterized by higher torque variation due to the use of square-wave switching. This type of motor also uses 1.22 times higher voltage compared to PM motors due to the use of two phases instead of three.
The use of permanent magnets in the motor (Fig. 4) almost completely eliminates losses on the rotor, which leads to increased efficiency.
The efficiency advantages of EC motors over traditional single-phase shaded-pole induction motors are greatest in the power range of several hundred watts. Three-phase induction motors typically have power ratings in excess of 750 W. The efficiency advantage of EC motors decreases as the equipment power rating increases. Systems based on EC motors and PM motors (electronics plus motor) with similar configurations (power supply, electromagnetic filter, etc.) have comparable efficiencies.
Three-phase induction motors are now widely used, with standard mounting and frame dimensions defined in IEC EN 50487 or IEC 72. However, many PM motors use other standards. A typical example is servos. With their compact size and long rotor, the servo drives are optimized for highly dynamic applications.
PM motors are now available in standard IEC compliant frame sizes, allowing the use of high efficiency permanent magnet motors in existing systems. This allows older three-phase induction motors (TPIM) to be replaced with more efficient PM motors.
There are two types of PM motors that comply with IEC standards:
Option 1: PM/EC and TPIM motors have the same frame size.
Example. The 3 kW TPIM motor can be replaced by an EC/PM motor of the same size.
Option 2: The PM/EC motor with optimized frame size and the TPIM motor have the same power rating. Because PM motors typically have a more compact size with comparable power levels, the frame size is smaller than for a TPIM motor.
Example. The 3 kW TPIM motor can be replaced by an EC/PM motor with a frame size corresponding to the 1.5 kW TPIM motor.
EC+ technology
Danfoss EC+ technology was developed in response to customer demands. It allows the use of PM motors in conjunction with Danfoss frequency converters. Customers have the opportunity to choose an engine from any manufacturer. This way, they get all the benefits of EC technology at a relatively low cost, without losing the ability to optimize the entire system as needed.
Combining the most effective individual components within one system also provides a range of benefits. By using standard components, customers are independent from suppliers and have easy access to spare parts. There is no need to adjust the installation connections when replacing the engine. Commissioning the motor is similar to commissioning a standard three-phase induction motor.
Benefits of EC+ technology
standard three-phase
induction motor
(bottom) and optimized
PM motor (top)
The advantages of EC+ technology include the following factors:
- Possibility to select the motor type used (permanent magnet motor or asynchronous motor).
- The engine control circuit remains unchanged.
- Independence from the manufacturer in the selection of engine components.
- High system efficiency is achieved through the use of high-performance components.
- Possibility of upgrading existing systems.
- Wide range of rated engine power values.
- Noticeably reduced weight and dimensions of the equipment (Fig. 5).
In addition to the advantages listed above, one more feature of EC+ technology should also be noted. The fact is that conventional electronically commutated fans cannot provide performance higher than the rated one, since they have a speed limit. At the same time, fans built according to the EC+ architecture can be accelerated to higher than rated impeller rotation speeds. In practice, this means the possibility of increasing the air flow above the nominal one.
In addition, the operation of EC+ motors can be controlled via the network protocols BACnet, ModBus and others.
EC+ technology from an end-user perspective
Separately, it should be said about the view of EC+ technology from the point of view of end users (as a rule, these are specialists in the design, installation and operation of ventilation systems):
Familiar technology. Many professionals have been using standard Danfoss VLT HVAC Drive series motors for a long time. The configuration of PM motors is almost identical. The user only needs to enter new motor parameters into the building management system. The principle of monitoring engine operation remains unchanged. Thus, controlling different types of motors within one system is not difficult. It is also possible to replace the standard induction motor with a PM motor.
Independence from the manufacturer. Users have the flexibility to customize systems by selecting standard components from different manufacturers. Optimal system performance. The only way to achieve optimal performance is to use the most efficient components. Users who want to achieve maximum energy savings must not only use efficient components, but also have an efficient system built around those components.
Low maintenance costs. A disadvantage of integrated systems is often the inability to replace individual components. Worn parts (for example, bearings) cannot always be replaced without changing the engine itself, which can lead to serious costs. The operating principle of EC+ technology involves the use of standard components that the user can change independently of each other. This allows you to minimize system maintenance costs.
Thus, EC+ technology seems very promising in the light of modern trends in energy saving and increasing the degree of controllability and manageability of various elements of the building’s engineering subsystems. The versatility of the technology should also play a role - the possibility of its application on previously installed equipment.
Yuri Khomutsky, technical editor of the magazine “CLIMATE WORLD”
The article uses materials from Danfoss technical documentation.
