Fan management - variable speed and fixed speed fans

[otrotabi]

When using compressor racks with both variable speed and fixed speed compressors - which is the most used scenario-  the CompMgmtVS FB has the built in logic to handle this setup.

A similar setup is used also for condensing pressure control, meaning that there typically are some fixed speed ON-OFF fans and variable speed fans. However this does not seem to be covered by FanMgmt FB which, as far as I understand, seems to assume every fan is a variable speed fan.

So, two questions: 1) Is my understanding correct, or by properly configuring some inputs the FB while handle this and 2) in case I am right, is there another FB I could use for this setup.

I need to control a very simple chiller with one EBM EC fan and one AC fan.

[FedericoM · Accepted solution]

Hi,

FanMgmt assumes that in case the VSD is present, all the on Fans are driven at the same frequency.

If you want to drive fans like compressors, I think you can reuse the CompMgmtVS even for fans.

You can reuse also the CompCntrl_VS or generate the value of usiStatusC1-C2 based on the Fan required and the related alarm status.

Other useful blocks are:

- EcFanMgmt under Application-->Air library

- EBM modbus blocks under Communication-->EBMpapstModbusCom library