The motorized valve connected to the Eurotherm PID controller that modulates the cold water on the fan coils in the room was found to be faulty.
With the fan coils out of order, the air conditioning was done only by the split installed in the room, which as we have seen caused the temperature to drop to 16° C because the air from its vent comes out at 10° C and it seems that the split also has regulation problems, since set to 20° C the temperature in the room drops to 16° C so its actual functionality remains to be verified.
What complicated the diagnosis is that someone had set a time program on the split, so even though it had been put on stand-by, at a predetermined time it would turn itself back on, and this explains the sudden drops in temperature in the room. So, at that point, on Thursday 12th evening we turned it off completely ( https://logbook.virgo-gw.eu/virgo/?r=65791).
We have manually adjusted the three-way valve that powers the fan coils (setting it to about 50%), so the temperature, although not regulated in feedback, remains at a value necessary for the correct functioning of the devices (we are between 18.5 and 19.5 C).
Obviously it is a containment action, for the time necessary to find a new motorized head to drive the valve with the Eurotherm PID.
This week the TSS (EGO Technical Systems Service) will verify the correct functioning of the split, which we have currently taken out of service, in order to restore the system redundancy for cooling the room.
