The reason of my post is to ask you something regarding ventilation in generator compartment. For example:
In this moment We have the ventilation fan A working with positive pressure. When We change to fan B we have negative pressure and fan A start again.
We already checked fan rotation, its OK.
We checked differential pressure transmitter, its OK.
We checked the dampers, are OK.
We checked air leakage from turbine enclosure, its OK.
What I see is
When We start the turbine, the pressure in generator enclosure it's ok. the problem is when the generator start to increase speed to 3600 rpm. In this moment the pressure in generator enclosure decrease to pressure alarm and start other fan.