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Case Study 1

T-Shirt printing machine

An 8 station T-Shirt printing machine suffered a PLC memory failure. We were called in to see if we could replace the PLC and re-program the machine due to original program not being available.

PLC was replaced with an ABB PLC and re-programmed enabling normal operation within 3 days. Additional features were added to the program to allow the company to have flexibility in the speed of production which was not available before. This was achieved through timing adjustments based on a multi-position selector switch.

Case Study 2

Wind turbine Power regulation.

A farm site running two 100kW wind turbines and a combined heat and power (CHP) plant wanted to cap its maximum power generation to 200 kW in windy conditions.

AN ABB PLC was installed with network connections to the Turbine network and was programmed to talk through MODBUS to the wind turbines and alter their peak power output accordingly. The power generated was taken from a power meter through an analogue connection into the PLC to allow for a total power reading to include the CHP.

This was successfully achieved and an average power produced across 10 minutes was used to regulate power to within the prescribed specifications whilst allowing for maximum power generation when not exceeding the average power limit.

Case Study 3

Roofing Felt machine

Large machine (100m Long x 10m High x 5m wide) had been brought over from Italy and mechanically installed. The machine makes Roofing Felt in a continuous process that then cut and rolled the felt into specified lengths. The PLC’s on the old machine were obsolete so were replaced with new ABB PLC’s. We re-wrote the programs due top originals not being available and also to accommodate new changes to the machine. There was also a large amount of electrical work to be done to re-connect the 70 or so motors for which we hired a local Electrical company and project managed this process alongside our own work for the customer.

There were 4 different PLC’s installed on various parts of the line to allow for various aspects of the project and also allow for future expansion as required. Touch screens were also installed to remove some of the many pushbuttons and to allow for greater operator information on line status.

Case Study 4

A company in West Wales design and build Stud and nut feed systems for a wide range of applications.

This project involved a stud feed system that provided a stud into a 600 Ton Sheet metal press for a car parts manufacturer. I became involved when the machine had been out at the customer for several months with ongoing technical issues which had not been resolved on site. At this point the machine was brought back to the UK and I came in to see if I could diagnose the faults and see what could be done.

Due to the ongoing issues the system was only allowing a production process of approximately 500 parts per hour with relatively long restarts afterwards to get back into production.

After spending some time with the designers and electrician, the fault was diagnosed as two distinct problems:

  • Firstly, the PLC that had been used was now obsolete and had been unable to detect the cycle go command from the press consistently due to the amount of time the signal was present for. This caused numerous stoppages to the press and therefore production suffered.
  • Secondly, when there was a fault the stud feed system had been made in a complicated way for the operator so that if the pressed an incorrect button out of sequence, the system would lock and they would have to clear out the studs and start the process again which proved to be both time consuming and frustrating for them.
  • Further to these two problems, there were also small issues with the Pneumatics and some of the sensors in terms of their position and type.

The fix once the problems were identified were relatively simple

  • Part one was to put a modern ABB Eco PLC in place of the old PLC. This new PLC has a faster cycle time and so would pick up the small signal from the press each time in ran through its start point.

This also meant that the programme had to be re-written and was done in such a way as to simplify it and allow for future upgrades to the system such as additional feed heads.

  • Part two was to simplify the operator interface, the old system had 15 pushbuttons on the control panel, some of which were obsolete but had carried the ability to interfere with the previous program.
  • These buttons were removed and the total button count went from 15 to 7. The program was used to make the next button in sequence to flash when an action was required by the operator and significantly simplifying the operator process on start-up.
  • The final part was to go through the system completely and look at how the other parts such as the Pneumatics and sensors were working. Through solving the PLC issue it highlighted that some of the sensors were not working in the best way so these were repositioned and a couple of them changed to optical sensors which allowed for greater precision.
  • In addition to this I then spent time with the operators of the machine teaching them how to use it effectively and also how to fault find any issues that came up and how to fix them. This means that any issues that do occur can be resolved quicker and allow production to start with much reduced downtime compared to the prior to the changes.
  • We were also able to provide phone support as required to them.

As a result of the improvements made over the course of a few days, the system went from running poorly (500 parts per hour) and inconsistently to producing over 900 parts per hour over longer production runs.