Pivoting towards rapid troubleshooting
Eaton's SmartWire DT wiring and communication system simplified wiring, reduces commissioning and maintenance effort for Herrenknecht AG
“The M12 technology also makes it very easy to replace the sensors in the field, this means that faults due to defective devices can be very quickly rectified. In addition, all positioning sensors, light curtains and limit switches are integrated into the PLC via Eaton’s SmartWire-DT – so that no additional digital inputs or I/O cards are required in the PLC – and it is also possible to diagnose pushbutton faults, etc. via remote maintenance.”
Background
Maschinen- und Stahlbau Dresden (MSD), a subsidiary of Herrenknecht AG in Schwanau, Germany, specializes in the construction and modernization of customized turntable systems. MSD’s products range from small turntables with a diameter of less than three meters and a load capacity of up to 40 tons to turntables for large vehicles with a diameterof 40 meters and capacities of 120 tons and more.
One of MSD’s latest projects is a turntable with a load capacity of 100 tons, which was installed at Bombardier Transportation’s Bautzen plant in Germany. It is part of a €30 million project by the world’s leading supplier of railway technology to expand its Bautzen facility.
The company had already implemented various machine building projects at the Bautzen site, Bombardier partly commissioned the turntable from MSD to achieve synergies in maintenance and inspection. “Due to the cabling, conventional turntables can only rotate by up to 270 degrees. By contrast, MSD came up with slip ring-based turntable design that can rotate 360 degrees,” says Mario Wagner, the engineer responsible for the project at Bombardier Transportation, highlighting a major advantage of the MSD turntable.
Challenge
However, the various control options, as well as the sensors (e.g. limit switches) and multiple automation components required for operation, including indicator lights, illuminated push buttons, emergency stop switches, RCDs and motor-protective circuit breakers, also need to be networked and supplied with power.
Since the turntable is located outdoors, some of the components are exposed to the elements, with a wiring distance between the control panel and the outdoor devices of up to 100 meters. The robustness of the turntable was another important criterion for Bombardier: Since unplanned downtime would prevent the final acceptance and thus the delivery of Bombardier’s vehicles, any faults need to be quickly identified and rectified.
Solution
MSD decided to network all components using Eaton’s SmartWire-DT communication system. This means that the individual switching devices, sensors and drives are not directly wired to the controller via classic point-to-point wiring, but that all participants can be quickly and easily connected via a green eight-pole cable with simple plug-in connectors. The SmartWire-DT cable supplies the connected devices with power and simultaneously handles the communication of data.
Up to 99 participants can thus be connected, and the maximum permissible cable length is 1,000 meters – in other words, more than enough for the wiring of the turntable. “The system not only ensures low wiring costs inside the control panel, but also in the field,” emphasizes Niels Kremtz, project engineer at MSD.
While a ribbon cable is used inside the control panel, the outdoor SmartWire-DT components are connected using a 5-pin circular connector with IP67 protection. So-called T-connectors are used to integrate the individual sensors, switching devices and signaling devices directly into the SmartWire-DT network via M12 connectors. The T-connector portfolio includes versions with different features: with one or two M12 connectors, with input or output modules only, and with temperature modules, analog modules or user-configurable I/O modules. MSD also installed a T-connector with an additional external 24 V power supply for voltage amplification in order to provide sufficient power for all connected devices.
Result
Easy remote maintenance and minimized downtime Connecting the various devices via SmartWire-DT and M12 connectors significantly simplified the wiring of the system and reduced the commissioning time of the turntable. “The M12 technology also makes it very easy to replace the sensors in the field,” adds Niels Kremtz. This means that faults due to defective devices can be very quickly rectified.
“In addition, all positioning sensors, light curtains and limit switches are integrated into the PLC via SmartWire-DT – so that no additional digital inputs or I/O cards are required in the PLC – and it is also possible to diagnose pushbutton faults, etc. via remote maintenance”.
The pushbuttons and emergency-stop/power-off buttons are monitored down to the contact elements. “The remote monitoring with direct fault detection of individual components is one of the main advantages of this solution,” says Bombardier, project engineer Mario Wagner.
“This prevents unplanned downtime, or at least keeps it to a minimum. Compared to older turntables without SmartWire-DT, the system implemented by MSD thus offers significantly higher availability”.
