An important electrical parameter in CNC machine tool equipment is the effective power of the electric motor. By using Phoenix Contact's Contactron motor manager, this parameter can be accurately monitored, and high overload and low load operating conditions can be immediately detected by this instrument. Due to the ability of the motor manager to issue timely alarms and maintenance reminders before the motor malfunctions and shuts down, it can effectively protect the machine tool equipment and significantly improve its usability.

In industrial applications, electric motors are generally used to start production. In general, it is protected by a motor current protector that functions according to the length of overcurrent time; Alternatively, it can be protected by a motor protection switch that provides overload protection based on the size of the load. But what happens to the motor when the cooling fan of the motor reverses, or when the cooler is blocked and unable to achieve normal cooling?

FDT/DTM software for parameter assignment, fault diagnosis, and production data collection

Current monitoring is often insufficient

Undoubtedly, when the temperature of the electric motor rises to a certain critical value, it will lead to the failure and damage of the motor. As a solution, a thermistor can be installed in the winding of the motor and connected to a control switch that can cut off the motor current when the motor temperature is too high. Thermistors and temperature control switches together constitute comprehensive protection for electric motors. However, this protection scheme has almost no protective effect on subsequent mechanical equipment or structures, and cannot avoid their failure even in the worst working conditions.

The main reason for the failure of electric motors is that many users have too few varieties of motor variants in stock to reduce inventory. In practice, about 90% of electric motors only reach 40% to 60% of their rated power working load, which is not within their operating characteristic range. And the overcurrent protection devices of these motors are set according to the rated power on the motor nameplate, and are set according to the parameters of the motor within the optimal operating characteristic range. When the load changes, even small changes will be reflected in the power factor and efficiency; The variation of electric motor current remains almost unchanged. However, mechanical devices may still be overloaded, while pure current monitoring systems will not display any issues. This will bring serious consequences to the machine tool equipment: the mechanical device driven by the electric motor will be severely damaged, and the cost will be expensive.