Blog4 - EN

Remote Commissioning of a S7-Controll for a Cooling System

Due to the pending quarantine regulations in China that requires a couple of additional days if not weeks, we decided to go for a remote commissioning of a cooling system together with our partner Kälteconcept using Skype and Teamviewer.

The plant itself, a subcritical CO2 Fluid-cooling-appliance was in central china, used in a wind tunnel of a Chinese Automobile Company, is designed for up to 850 kW cooling power. It consists of 2 parallel compound lines with 3 CO2 compressors each, partially controlled by VFDs.

Practically it was done with Tia-Portal V15 on a S7-1500 CPU with a TP900 Comfort-panel. The special feature is a Pre-Error-Archiv was saves, in case of a fault, all relevant system data for the last 30s BEFORE the error occurred.

Finally it was a total success with only winners. The end user saved some money and was practically forced to an intensive training, we avoided a long commissioning trip with a unpleasant quarantine and finally the environment wins by avoiding flight traffic. A random view at the sky above our house compared to one on feb. 21rd in 2012 speaks for itself.

Particularities of Brushless-DC Motors – Part1

It’s known, that the commissioning of larger projects takes longer and not anything can be expected in advance. One of our big FFU partners experienced this at firsthand. Normally the FFUs with its EC-Motors, that partner calls Brushless-DC Motor, will be mounted, wired and the belonging controllers individually addressed and finally powered-on section wise. Afterward the line will be scanned by a special control tool for those brushless-DC Drives, a possible wrong addressing corrected, followed by a short test run launched by control device whether anything is ok. At the end of this procedure you “get” a line that is addressed correctly and capable to communicate. Finally the line will be set to sleep per Stop-command, and not via power-off, for being ready for higher tasks.

If now, due to what reason ever, most of the FFUs with its Brushless-DC drives run at nominal speed the cleanroom will be set under pressure. Subsequently those fans being simple powered-off start to run in reverse mode. Now the Brushless-DC Drives show their particularities. The Brushless-DC Motor starts to windmill and operates as generator and charges via the reverse diodes the DC-link of the controller as long as the internal power supply and therewith the BUS-communications start to “work” or better to get to half asleep. The sent order sequences are a kind of half correct signal noise that is overlay the normal communication of the FFUs that are running powered-on at normal speed, what we are supposed to filter now. ... to be continued!

Cleanroom catalogue - ebmpapst

The most important point seems to be that there are special parameter sets for each of the relevant BUS systems (ebmBus, ebmBus/DCI as well as Modbus and Modbus/DCI) what allows a line wise mixed operation of these different fans at one single FFU-Control-Centre. This is especially relevant for plant expansion.

FFU Service for Nicotra||Gebhardt EC fans

The last week before Christmas is normally the scheduled time for a production shutdown at a big cleanroom-site in Jena, where different suppliers and partners use this for their annual maintenance. So the FFU System, delivered with EC-fans from Nicotra||Gebhardt, once commissioned by vbk technology and since that supervised by us, was checked as well. As the FFU-Server has been switched to a virtual platform in 2020, no investigation of the server hardware has been required this time.

Finally a measurement of the pressure-drop of a certain number of EC-FFUs took place. Therefore the existing aerosol-hose network was used, we could dispense to access the cleanroom.

EC-Control Device

The long wait ends right now. Besides to all joy the look at our interactive costumer card triggered some mixed feelings at CEO Mathias PAUL. Still “grey” was our beautiful neighbour country, as a part of the bloodline of his grandfather started in the Steiermark/Austria. But this is now to end. From now on a large player for electronic lengths measurements will control parts of his cleanroom by using control devices for EC-drives made by vbk technology.

The question remains – and our adorable neighbours will forgive us the joke - what are they really going to do with that, believing @realDonaldTrump „They live in the forest“ we have some doubt if it is to control FFUs with EC-fans in cleanrooms whether from Nicotra||Gebhardt, ebmpapst, Ziehl Abegg or Rosenberg. ;-)

Rosenberg Modbus Gen2/3

One of the big cleanroom players in the US planned to use Rosenberg EC-fans for its FFUs for a cleanroom project. So our task was to create a firmware update for our EC-Fan Control device uniqunet to control exactly these fans. As the handling of the reading- and writing-register of the Rosenberg Modbus is kind of tricky it was a bit of a challenge to get this integrated inside the package-commanding structure of the uniqunet control device.

At the end there is besides some compliments from the costumer an appealing hardware order, of course including the new firmware.