Hitachi RCI-2,0-FSG2 - Ventilation speed variation

[Rafael Brazil]

We are facing a problem at one Hitachi RCI unit, part of a Set Free system.
The first problem was the freezing sensor, which we have already replaced by a new one.
Now, the ventilator is oscilating its speed. That speed up and slowdown without any user command.
The air comming from the RCI is at the correct set temperature. So, I assume the refrigerating gas is circulating in the unit.
The problem is the speed of the ventilator indeed, that doesn`t keep running continously.
Does someone know the possible reason of this problem ?

Thank you in advance.
Regards,
Rafael

[al]

Check the refrigerant charge, i think fan speed is dictated by coil temperature. Also check the evaporator fan motor is not over heating and tripping itself out.