Overview of Danfoss Micro Drive Frequency Inverter And Its Functional Analogues

Table of contents

1. Advantages of using Danfoss VLT MicroDrive
2. Features of the compact Danfoss MicroDrive FC 51 series
3. Danfoss closest analogues by functionality
4. Comparison table of Danfoss Compact series analogues

Electric motor control systems based on frequency inverters relatively recently have been implemented, but the opportunities offered by such solutions have led to the fact that every year equipment based on synchronous and asynchronous electric motors is increasingly equipped with frequency inverters.

There are enough solutions of different manufacturers on the market that allow designing and implementing effective systems of such control in various sectors of activity, from industrial solutions to inexpensive household equipment for private use. Obviously, in the field of off-the-shelf technical solutions there are their leaders, whose products are in high demand because they have good indicators of functionality, reliability and cost.

For the global market, and especially for the EU market, such a leader is the Danish company Danfoss, which offers solutions in the field of power engineering, control systems and industrial automation. The company offers equipment that is focused on specific applications and allows controlling both low-power loads and electric motors with several hundred kilowatts of power. It is obvious that the scope of application of low-power AC frequency drives is much wider and covers almost all types of activities. However, the advantages of implementing such low-power frequency inverter solutions have the same key advantages as powerful equipment for complex industrial applications.

It is for such solutions that the company offers the Danfoss MicroDrive range of frequency inverters, whose models allow the control of electric motors with a power from 370 W to 22 kW. This is the power rating at which most of them operate:

• domestic and small industrial pumps;
• machine tool motors and servo drives of various types and applications;
• motors operating in ventilation systems of small objects;
• hoists, electric winches, low-powered crane equipment;
• electric compressors; 
• and a variety of equipment that includes an asynchronous type electric motor.

Advantages of using Danfoss VLT MicroDrive

The compact series of products from this manufacturer has advantages that are inherent to modern frequency inverters:

• precise control of motor starting and braking modes according to a preset curve;
• reverse function;
• increased torque at low engine speeds;
• increased speed range of the electric motor as compared to direct connection to the mains;
• protection against overloading, overheating or jamming, which prolongs the life not only of the motor but also of the accessories connected to it;
• energy saving;
• possibility to connect feedback sensors for precise maintenance of the monitored parameter;
• easy setup with the help of the control panel as well as the computer program with an easy-to-use graphical interface; 
• a detailed manual describing all parameters and different setting options;
• availability of a solution for both single-phase and three-phase AC networks; 
• possibilities of integration into a unified control system and remote dispatching.

Besides, equipment design on the basis of Danfoss VLT Micro Drive FC 51 compact series allows saving due to reduction of number of additional components, e.g. safety valves, sensors, thermostats and other devices, used for motor protection against overload operation.

Features of Danfoss MicroDrive FC 51 compact series

The popularity of this company's products, in particular the compact series, is due to one of the best combinations of cost, quality and functionality. These frequency inverters allow adjusting about 100 parameters, which determine motor operation modes and other equipment functions, to the specific features of the developed system. The key features of the compact series include:

• high-precision vector control of the motor by voltage and frequency of the electric motor supply;
• the built-in proportional-integral feedback controller allows you to accurately maintain the setpoint (e.g. pressure or airflow rate);
• automatic motor adaptation mode is provided, which allows you to quickly start the equipment without going deep into the settings of start-stop curves and other adjustable parameters. In this case, only the key characteristics of the electric motor should be stored in the controller memory;
• the built-in controller with the ability to program logical operations allows to build quite complex systems based on frequency inverters with analysis and processing of data coming from external sensors. For example, it can be a control of machine tools based on signals coming from the sensors of working tool end positions;
• possibility to program and adjust all parameters of the compact series frequency inverter both via removable control panel and via computer using several communication protocols. A software tool is included with the frequency drive for easy setup and analysis of the operating mode;
• possibility to copy the settings made from one frequency inverter to all equipment of the adjusted equipment batch under control of frequency drives of the same type;
• built-in protection systems against overload, excessive temperature, short circuits, phase failures in both power supply and load circuits;
• the integrated power adaptation function allows for cost optimization. Despite the small capacity of the motors controlled by the compact series, the savings can be significant when used on a mass scale (in production);
• the built-in EMC filter minimizes interference that can adversely affect the stability of other equipment connected to the same power grid;
• a wide range of accessories that expand the capabilities of the frequency inverter, increase its reliability or security, facilitate mounting on rails or in switch cabinets, makes the frequency inverters of this series even more versatile.

Separately we should say about the design of these low-power frequency drives, which are characterized by their compact size and such features:

• frequency controllers are made in a sealed housing, because they do not require forced ventilation of the internal space, due to high efficiency and efficiency of up to 98%;
• the heat dissipation from the power elements is done through the heat sink to the outside of the device;
• the frequency inverter PCBs are coated with a layer of varnish and compound to further protect the components from moisture and reduce the probability of breakdown;
• The compact enclosure of the frequency inverters is designed so that it can be mounted in the equipment, on the rail or in the cabinet close to the back wall. The switching panel is located on the bottom edge to save space and provide easy access for maintenance of contact groups, connection of power cables, sensors and communication systems.

Due to such design, the frequency inverter requires practically no regular maintenance, cleaning from dust and is able to operate at the ambient air temperature up to 50 degrees Celsius, which is enough to solve most technical problems in any climatic zones.

Also if you compare the products of this manufacturer in terms of price with the closest Danfoss analogues, taking the number of phases and power of the controlled motor as a basis, you can see that in most cases the compact series of this manufacturer will be cheaper to buy. However, the counterparts should be said in a little more detail.

Nearest Danfoss functional analogues 

Despite the fact that the manufacturer's products have a good reputation and have a wide range of configuration options, sometimes it is technically necessary to use counterparts. 

They may differ, for example, in terms of configuration features, functionality that Danfoss does not have. The need for replacement may also be due to the unavailability of the required model on the market, when the equipment needs to be upgraded or repaired urgently.

If you need to replace Danfoss with similar products with the closest specifications, consider ABB and Schneider Electric's compact ACS150 and Altivar 12 series respectively.

To make it easy to compare the performance of these series of inverters, we offer a comparison table of the key parameters of the products of these manufacturers.

Comparison table of Danfoss compact series analogues 

Comparison parameter	Product line name
	Danfoss Micro Drive	ABB ACS150	Schneider Electric Altivar 12
Appearance
Power range of single-phase load, kW	0,18 – 2,2	0,37 – 2,2	0,18 – 2,2
Three-phase load power range, kW	0,37 – 22	0,37 – 4	0,18 – 4
Type of control	Vector U/F	Scalar U/F	Scalar U/F & Vector
Availability of EMC filter (Electromagnetic compatibility filter)	Yes	Yes	Yes
Type of feedback control signal	PI controller	PID controller	PID controller
Mounting possibilities	On the plane, on the rail	On the plane, on the rail	On the plane, on the rail
Control panel	Removable with copyable and transferable settings	Built-in	Built-in
Supports remote control protocols	Yes	Yes	Yes
Price of frequency inverter for three-phase network with load capacity of 0.37 kW	€105.12-217.54	€169.74-341.55	€122.00-208.00

If you find it difficult or do not want to spend time on the selection and comparison of the required compact frequency inverter for the construction of motor-based systems, you can always ask for help from our company.

You need to provide the requirements for the future system and its key characteristics, on the basis of which our staff will select the appropriate model of frequency drive for you.

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