A 3 ton calibration trolley runs on 250m long rail track over a 3m width 2.5m depth water canal. This is a unique kind of equipment of which there are only about 30 in the world. It drags along the meters to be calibrated. The existing system was 50 years old and had strip chart recorders. Speed was manually controlled. All calculations were performed using readings from the recorders. Getting the end result would take days of processing.

This project was to modernize the trolley by replacing its power transmission system and drive mechanism and providing computerized data acquisition and processing system so as to achieve precise speed control in the wider speed range and better accuracy of measurement.

The system is now retrofitted with state of the art servo drive control system on each wheel for accurate speed control and stability. The servo system consists of four-wheel independent synchronized drives. The data acquisition system supplied is based on a Siemens PLC with a SCADA. Recipes for different tests are stored in the database using SCADA system. Speed profiles for various tests are maintained by the PLC with recipe information from the SCADA. All manual intervention is now redundant for current meter testing. Results are printed as soon as the test is done.

Turnkey project included putting up the overhead power system, design and selection of servo motors, gear boxes, data acquisition system, mechanical assembly of the entire system, Software development & commissioning of data acquisition system, parameterizing and commissioning of the drives.