The conveyor system for transporting cement clinker at the Lägerdorf production plant of Holcim (Deutschland) AG uses SmartWire-DT, Eaton’s innovative connection and communication technology (Fig. 1). SmartWire-DT is used on the conveyor line for transporting the clinker from the oven to the storage silos and for distribution into the silos using sliders (Fig. 2).
Capture process states
Recording process states and creating a clear and transparent monitoring of production processes are requirements that are gaining increasing importance. These aim to ensure the early detection of process faults or even process downtimes in order to make timely interventions and implement appropriate preventative measures. For this Eaton is offering a perfect solution made up of the PKE electronic motor-protective circuit-breaker, the NZM circuit-breaker and the SmartWire-DT connection and communication system.
The PKE reliably protects and monitors motor feeders up to a rated current of 32A. Consisting of a PKE basic unit and the PKE trip block the modular switch can be flexibly adapted to the current range to be monitored. The wide current setting ranges of the trip blocks also cover a number of equivalent, conventional bimetal overload relays which considerably simplifies the engineering of the main circuit.
The NZM circuit-breaker is used for protecting higher rated motors and systems up to 1600A. Like the PKE, an NZM with an electronic release can cover several conventional bimetal circuit-breakers thanks to its large current setting ranges. In conjunction with SmartWire-DT both switching devices only require a few simple operations to integrate into the control system. This gives you the option to transfer data about the state of the motor feeder and sections of the system to the higher-level controller. At the Lägerdorf plant NZM2 and motor starters (reversing starters and DOL starters) were each used with a PKE electronic motor-protective circuit-breaker.
SmartWire-DT is based on standard fieldbus systems such as Profibus DP or CANopen, thus enabling a simple integration into standard PLC programming systems (such as CoDeSys and STEP7) and SCADA systems. Each slave on the SmartWire-DT is automatically assigned an address on the gateway at the push of a button and in the order in which the slaves are connected. The individual slaves are not activated until the address is called. The SmartWire-DT software (SWD-Assist) supports the user during planning. It offers help in correctly selecting the function elements, suggests accessories and carries out plausibility checks. For network configurations (such as Profibus configurations) the software can also be used to create specific device description files (GSD file) which are then simply imported into the appropriate programming system.
Early detection of critical states
SmartWire-DT keeps mounting and wiring requirements to a minimum. The continuous green SmartWire-DT cable is a striking feature in the switchboard. It provides the communication link between the required components. SmartWire-DT furthermore eliminates the need for the entire control system wiring – the single SmartWire-DT cable normally provides the power supply required. Conventional I/O modules are also not used since the I/O level on SmartWire-DT is directly integrated in the switchgear, thus totally excluding the possibility of faults. SmartWire-DT therefore opens up the problem-free control and reading of process data. With the PKE and NZM this consists of both simple binary data such as switch positions and also more extensive messages such as causes of tripping and also analog data such as motor currents and the thermal load of a motor. The differentiated transmission of data provides users with new possibilities in monitoring and controlling processes. These range from increased transparency in manufacturing processes (moni-toring) to the early detection of critical states or failures right through to preventative maintenance management.
Designing processes with
Gerd Sievers, in charge of system planning and engineering at the Lägerdorf plant, summed up as follows: “We were looking for an intelligent motor starter for controlling the conveyor belt for our clinker production. We found what we were looking for at Eaton. The SmartWire-DT system currently integrated in our switchboards offers us a high level of reliability and secures product quality. Even more important for us was the fact that SmartWire-DT enables us to design our process with greater efficiency, transparency and clarity (Fig. 3). If required, it is also possible to exchange components during operation. We were able to fully implement our switchboard concept with SmartWire-DT. The host of functions provided exceeded our initial planning specifications, such as the system-immanent manipulation protection, the extremely precise diagnostics or the presettable values in the SCADA system – SmartWire-DT offers us considerable added value.”