Electronic Devices Repair

Repair of Frequency Inverters

Promatis repairs single phase and three phase high and low power frequency inverters (0.75kW-250kW).

We specialize in repairing frequency inverters of renowned global manufacturers such as Allen Bradley, Vacon, Handtmann, Invertek and Gefran. 

Upon request, we also repair to order other electronic devices that are used in the automotive industry, medicine or general electronics. 

Examples of Our Work

Here you can see some examples of our work

More on Frequency Inverters…

The most commonly used industrial motors are operated by changing the FREQUENCY of voltage.

Devices that change the frequency from the standard 50 Hz, which are used in the whole EU, are called FREQUENCY INVERTERS. Promatis specializes precisely in the repair of these devices.

All frequency inverters function in the same way. The rest are just nuances in electronics, such as different possibilities of communication between the user and the machine. The input voltage of frequency inverters can be single-phase or three-phase (220V or 3x380V), depending on the power. This voltage is converted into DC voltage (600V ~ 800V DC). With different oscillators and sophisticated devices, microcontrollers, this voltage is cut and converted into a voltage of higher frequency (mostly 0-460Hz), which is later sent to special power transistors known as IGBTs. IGBTs then manage the voltage which comes to stator windings of the motor. That way we control the rotational speed of the motor, as well as the torque of the motor.

More on Electric Motors…

Different types of motors are in use nowadays. The major categories are:

a) those for DC
b) those for AC voltage and current.

They can also be divided into:
a) motors in which the electric current in the rotor is induced by electromagnetic induction from the magnetic field of the stator winding,
b) motors in which the control voltage and current are led to the rotor, and the stator contains static magnets.

Due to their small mechanical size and high efficiency in industrial plants, asynchronous motors are used most frequently (power supply and control through stator windings). They can be either single-phase or three-phase.