Keckeis Elektrotechnik GesmbH & Co KG: "Winter-Proof"
Drive Monitoring with SmartWire-DT™ and PKE
Under the management of Manfred Keckeis, founder of Keckeis Elektrotechnik GesmbH & Co KG, Rankweil/ Austria, the former installation company has specialized in the last 20 years in two areas – ski storage systems and control tasks in the building materials industry. Keckeis can add several reputable tunnel projects as well as major building projects in Europe and in the Arab Emirates to its list of references.
Experts in the field know the problem of starting iced up elevating conveyors in the morning in freezing temperatures all too well: The stiffness of the empty conveyor belts due to frozen water in the belt pockets causes the motor currents to increase right up to the operating limits. When material is then added, the drive enters the overload range and the motor protection shuts down the conveyor. A restart is then mostly only possible after the conveyor line has been emptied by tediously shovelling off the conveyed material by hand.
After upgrading the sand and gravel plant of Kekeis Elektrotechnik GesmbH & Co KG, with SmartWire-DT, the iced up belt can be automated to “run warm” until the operating current has dropped to “idle running”, and only then is material conveying enabled. Any accidental material conveying and likewise any excessive warm running are prevented. A far greater benefit for BSL is the controlled operation of the plant close to its maximum output limit, i.e. optimized and safe plant operation.
This is because varying total weights are transported at the Lorüns crusher and screening plant, due to the humidity and grain size of the transported material. The outstanding benefit is the enhanced drive monitoring functions: The actual motor current can be displayed and evaluated continuously without the need for any expensive analog I/O technology.
With conventional motor control using motor-protective circuit-breakers and contactors, the switching states of both components (ON) are interrogated to make an indirect evaluation of the operating state and the detection of a standstill. A hardware solution such as a speed sensor, load shedding relay etc. is required for a real and reliable feedback signal. When the set current value of the drive is exceeded in the event of an overload, the drive is shut down immediately in order to protect the motor from being destroyed and a fault is indicated. This results in several unplanned breaks in operation that can take a lot of time to rectify and often involve high downtime costs.
It is in this particular aspect that SmartWire-DT shows its tremendous benefits: The evaluation of the actual operating current makes it possible to distinguish between the following six operating states at BSL (according to the drive task):
- Motor switched off
- Motor underload
- Motor idling
- Motor operation
- Motor overload
- Motor fault
The individual load limits as well as the time characteristics can be programmed as required for the particular drive application at hand. This enables the plant operator to detect imminent faults early on and enables interventions in the production process before an unscheduled interruption occurs.
Manfred Keckeis, general manager at Keckeis Elektrotechnik, Rankweil/ Austria, made this assessment: “The decision made jointly with BSL to not only upgrade the power section but also to replace it with SmartWire-DT in combination with Eaton‘s PKE electronic motor protection has not only paid for itself very quickly in terms of investment but also in terms in system availability. As well as the neat and extremely fast “wiring” of SmartWire-DT, its space saving design was particularly ideal for the limited space available in the control room. The aim is also to give our customer a convenient solution that is easy to operate. SmartWire-DT‘s status messages and self-diagnostics options are therefore a tremendous help.”
Junior boss Michael Keckeis also had this to say: “SmartWire-DT with PKE offers a host of benefits when reliable feedback signaling and a high level of system availability are required. SmartWire-DT is Eaton‘s logical further development in response to the market demand for intelligent switchgear – an attractively priced combination of proven switchgear and upgraded with the SmartWire-DT communication and connection system.