data rooms

[Sledge]

FALSE ALARMS : EG. LOSS OF AIR FLOW, FIRE AND SMOKE, WATER, HP, LP , ALL FALSE WHEN CHECKED OUT.

I am assuming that the fire and smoke alarm is local to the unit, not a separate fire alarm system.

For all 3 of the units to be generating these false faults;
-there must be either a common element that is causing these faults to be displayed, or
-there must be a design/installation flaw within the installation.

The nature of these faults makes me think that there is a design/installation problem, not a common element. I am assuming these are 3 stand alone units, and am doubting that there is a loose connection in all 3 units.

A problem with air flow within the raised floor would not cause a HP alarm, nor would it cause a water leak alarm, regardless of what may have changed in the raised floor.

You havent indicated any problem with the mechanical components. If the units are functioning and cooling, and the pressures/temperatures are all ok, then I would be hesitant about condemning all 3 units.
I would consider that this is a control issue only.

I would have a good look at the control circuit, with the attitude that there is a mistake there somewhere.
-Check the inrush current of all the contactor coils, and compare the totals to the VA of the control transformer. The transformer must be more than big enough to carry all of the coil inrush currents that it will see at any one time. Often the control transformer supplied with a unit is not big enough to power the remote condensor contactor, or remote devices.
-Check and see if the control board electronics are powered by the control transformer that powers the contactor coils. If this is the case, add in seperate dedicated transformers that are dedicated to powering the control boards electronics only. I would do this first!
-Check the output voltage from the transformer. I dont know what voltages you deal with in Europe, but we encounter various voltages in Canada, and it is easy to get the wrong voltage control transformer.
-Check and see if the secondary of the transformer is grounded, and then check the specs and see if it should be, sometimes it is a requirement, and sometimes it is a no-no, depending on the design of the circuit board.
-If it should be grounded, make certain that the correct side of the transformer is grounded.

Are the HP and LP sensors electronic, or are they simply control contacts? Is the TX electronic? If no to both...
Since this is nothing more than a glorified air conditioner, in a fancy box, I would disconnect the high tech controls, run it temporarily off a return air stat placed in front of the filters, with a temporary HP safety. If you can do this in a way that maintains power to the electronics, but doesnt allow them to trip the unit out, you will be able to run the units, and monitor the control faults at the same time.