Frequency Converter

The company is extending its range of modules of the Simatic ET 200X distributed I/O unit to include the EM 148-FC frequency converter. As a supplement to the known motor starter modules which only provide On/Off or Left/Right control, this unit can control with variable speeds. Thanks to its full integration in an ET 200X station and its high degree of protection of IP65, the frequency converter requires no control cabinet; it is fitted directly on the motor. Applications for the device are, in particular, conveying systems such as roller conveyors or lifting stations.

The heart of the EM 148-FC is based on the well-proven Micromaster technology. The power class of the controlled drives is 0.75 KW, allowing many of the conveying applications to be implemented with this solution. No additional software is needed for parameter assignment of the frequency converter. This takes place with STEP 7 or COM Profibus, as for all expansion modules. The parameter set has been reduced to simplify the handling. The filter element to avoid system perturbation is already fitted in the module. Also integrated are a brake contact for 400 V brakes and a thermistor evaluation circuit to protect the controlled motor from excess temperature.

The connection system of the converter module on the motor side is a plug-in arrangement, as for the motor starters, and is based on the DESINA standard. The supply voltage is simply fed from module to module with a single power cable, the energy bus. The motor feeder of the frequency converter is shielded to avoid interference to the environment.

Up to six frequency converters can be used per station. The module range of the ET 200X, extended to include the EM 148-FC, ensures precise matching of the distributed I/Os to the technological task.

N/A, Siemensallee 84, Karlsruhe, D-76181. Tel: 49-721-5954798; Fax: 49-721-5956235.