head pressure control

[wing]

hi guys, Our air cooled condenser has 5no 2kw fans controlled via a step controller and pressure switch. As an upgrade we were thinking of installing a vfd and presure tranducer to control the head pressure. Is it wise to have 5 seperate vfd or just 1?regards Wing

[chemi-cool]

Yes you will need 5 VFD's
But before you do it, consult the experts in fans:

http://www.ziehl-abegg.com/en/index.html

[littleyapper]

i would suggest one speed drive (danfoss akd type)or similar using a tranducer(sized accordingly).... then a change over relay controlled by a hp switch which will bring in your old step controller as a back up just in case ..... i use this system in all my packs .... great control with peace of mind...