As part of the electrotechnical refurbishment of the goliath crane the old S5 controls and the old converters have been replaced with new S7 controls and new DCM converters from Siemens. The general control concept of the crane was retained.
The original control cabinets for the low-voltage electronics, the PLC controls and the power electronics of the hoisting unit, trolley and travelling gear drives were assembled with new switchgears. Moreover, the hoisting units and the trolley driving gear were equipped with a Profibus Absolute Encoder in order to determine the lifting height and the position of the two trolleys.
The new S7 controls were implemented failsafe. With this it is possible to read and process all relevant inputs by avoiding failures. This also includes the emergency stop circuit. Previously, the emergency stop switches were integrated directly in the electric circuit of the low voltage coil of the crane switch. During the refurbishment the signals were also wired on the safety-oriented inputs of the PLC.
The crane drive includes a synchronization control. While in operation, the crane would normally only drive skewed within a few centimeters. If by any circumstances a misalignment of 300 mm is reached, the emergency stop switches will be activated on both sides. In this case the travelling gear will be mechanically braked and the crane switch will be disabled. Additionally, the crane is equipped with an overload protection system. In case of an overload the lifting is blocked and only the lowering is permitted.
There have also been installed two new visualization systems, one in the E-house and another in the driver’s cabin. Both systems are identical and consist of a PC and a touchscreen monitor. The current status of the drives and error messages are instantly presented. In this way, the crane drivers and the service technicians have an overview of the goliath crane’s status at any time.
To further increase availability, an app for smartphones and tablets was developed. This provides a precise overview of the system and the fault messages and is therefore used for quick remote diagnosis and support for service personnel
Why HIT?
HIT has completed this project to the full satisfaction of the customer and has maintained the facility since it was retrofitted. A good crane and software structure were created for the service team through a PC-based user interface. Besides, the HIT App provides the basis for a high-availability of the facility. From the very beginning, this goliath crane proved its reliability. These features increase the fault tolerance and the productivity of the system.
