When carrying out retrofits, WDS replaces outdated components with new, modern technologies, thereby updating older plants to the technical status of a new plant. Converting from hydraulics to servo technology or adopting customised solutions for the replacement of discontinued servo components give older machines a boost in efficiency, reliability, spare parts availability and service life.

WDS began converting old hydraulic depositor machines to servo technology in 2011, because many parts were no longer available and there are hygienic reasons due to the hydraulic oil. Advantages in terms of process engineering include more precise movement sequences and simpler operation.

WDS carried out an extensive series of retrofit measures for Continental Candy Industries B.V. (Netherlands). Because of availability of spare parts, CCI decided to retrofit the hydraulic depositors of the existing mogul plant type 361B (1983) with servo drives. In addition, a new switch cabinet and an up-to-date HMI were installed.

The customer also decided to install new hoppers, pump systems, a new feed unit and a new stacker and to replace all safety switches from 230 V to 24 V.

The entire process from placing the order to installation at the customer’s site took six months. Thanks to tests of the conversion parts at WDS, the installation and start-up on site could be completed by a team of 7 WDS and 6 CCI specialists within four weeks.

“The retrofit conversion to servo technology enables us to continue to operate our plant while meeting standards of safety, hygiene and profitability. The new plant control in line with the current standard enables us to produce with an improved OEE. Safety for our staff has improved and the new HMI control system has given us more insight into the performance of our machine.”, says John van Dongen, Project Coordinator at CCI.

When servo components were discontinued by Bosch in 2018, WDS developed solutions to preserve and modernise the machines. Customers using the PPC R02 servo control, DKC servo controllers and MHD servo motors were offered combinations of Bosch service contracts to extend the availability of spare parts and to replace the discontinued components. This required working with the customers to determine which model was suitable for their needs. The main questions are: How long is the plant expected to remain in operation? How much downtime could be allowed for the retrofit measures? WDS has already successfully completed projects involving the replacement of 2 to 104 servo axes.

During a retrofit conversion for one customer, 49 old MHD servo drives were replaced with new MS2N drives with new gears. In addition, the entire main switch cabinet was replaced with a new switch cabinet. All supply and feedback cables of the old servo drives were replaced with suitable hybrid cables and, instead of Profibus cables, complete Ethernet cabling was laid for all replacement components. Here too, a new HMI and state-of-the-art control units were employed to ensure simple operation after the conversion.