'Lean connectivity' technology slashes wiring costs for machine builder
05 October 2014
Mönchengladbach based Schaltanlagenbau Gormanns GmbH uses Eaton's novel SmartWire-DT technology for the electrical power supply and automation system serving a fully automated potato sorting plant.
The field crop business is a seasonal one. During high season, exceptionally large quantities have to be processed in a short time and so this new potato sorting plant was no exception, being designed to process as much as 120 tonnes of potatoes per hour through a variety cleaning and size sorting stages.
The process starts with the farmer delivering his potatoes to the collection point. The harvested crop is then fed via a hopper to conveyors that carry the product to the 'stone and clod' separator where unwanted material is removed.
In the subsequent pre-sorting stage, potatoes that are too large or too small are removed and passed on to a feed bunker. After soil is removed from the remaining potatoes, they reach the sorting machine, where vibrating screens separate them into seven categories according to size.
Here, they are manually examined in order to remove any bad ones. They are then washed, dried and polished before being transported to various bunkers that each hold 40 tonnes. Depending on the means of transport required, they are then weighed and bagged in nets, or loaded directly on a truck as loose items.
Just one operator is needed for the entire plant, to switch it on, and select between programmes (setting the potato size, defining routes or selecting or deselecting the washing operation, for example). The rest of the plant is fully automated.
Schaltanlagen Gormanns GmbH was originally a refrigeration and waste water technology business. In recent years, however, it has made a name for itself in the agricultural sector with both new building projects and conversions. Sebastian Gormanns, the founder and CEO of the company, takes up the story:
“When the agricultural company approached us to ask for support with this new project, we were attracted by both the capacity of the plant, as well as the complex challenges with regard to the required level of automation. We were given the task of getting the plant running correctly and on time, as well as ensuring a simple operation for everyone. Apart from that we were given a free hand.”
Having recently worked on a similar, smaller sorting plant where it had been responsible for everything from planning to commissioning a project involving around 190 drives, the company was well placed to take on this larger project, which entailed the installation of some 250 drives for conveyor belts, pumps, fans and machines. Based on his recent experience, Mr Gormanns estimated that at least 32 kilometres of cable would have to be laid for the entire plant, with at least one additional kilometre of cable for the conventional cross wiring within the switchboards.
He decided to use Eaton's SmartWire-DT connection and communication system, which allows components such as switchgear, sensors and actuators to be wired back to the machine control system via a single cable, as opposed to the many cables that would be required by a conventional wiring scheme. SmartWire-DT provides the individual slaves with power as well as facilitating data communication between all stations on the system. With this arrangement, a Profinet, Profibus-DP or CANopen gateway can be used to connect the system to a higher-level controller to enable data exchange via various fieldbus connections and controllers. Sebastian Gormanns again:
“Eaton provided us with a demonstration case so that we were able to thoroughly test the system over a week. We not only tested the technology, but also its openness for the PLC systems and components from other manufacturers. However, after completing an in-depth analysis I was both convinced and delighted with the product. I knew that the potato sorting plant would be an ideal project to fully utilise the benefits of SmartWire-DT.”
The main panel comprises a central unit with nine sections as well as a substation with four sections. Profibus is the fieldbus system of choice, via which the PLC, frequency inverters and touch panels are able to communicate with one another, while motor starter combinations networked via the SmartWire-DT system handle the switching and protection of all 250 drives.
These are connected by section to the PLC with one gateway per section, and consist of motor-protective circuit-breakers, contactors, and electrical connectors from Eaton's standard product range. Schaltanlagen Gormanns GmbH chose PKZ motor-protective circuit-breakers that are matched to the DIL contactor series. These switch drives in the sorting plant with operating currents of between 3 and 10A.
Some of the motors in the plant are reversing drives, whilst others are pole-changing drives. These can also be easily integrated using SmartWire-DT. And as well as its use in the main panel, SmartWire-DT is also used to connect in excess of 50 command points around the sorter machine. Sebastian Gormanns concludes:
“I have to admit that I was initially skeptical about whether SmartWire-DT could actually do what it promised. But I can now say with conviction that the installation was completed without any problems and that I have seldom seen anything so simple. For us, the wiring requirement has been reduced to an eighth of what it normally would be. Thanks to SmartWire-DT the cross wiring has been reduced from one kilometre to fifty metres, and the cabling required for the control circuit devices on the machines has been reduced by approximately 40 percent.
“Troubleshooting has also been considerably reduced since faults can be found quickly due to the high level of data transparency of the connected stations. Instead of the two weeks we required for commissioning our previous sorting plant project, we only needed one and a half days with this project. We were thus able to successfully implement this complex project in only four months. I am looking forward to the next opportunity for us to work with SmartWire-DT.”
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