61.Can it be possible to open the inlet vane of an IDF during trial run and why?

It may not be possible. The fan may be over loaded. A fan handle volume. When the inlet vane is fully open, the volume of gas/air will be the maximum. ID Fan handles flue gas at 120 to 140 Deg.C. The density of gas will be less compared to air

( Air density - 1.29 Kg/M3 at 15 Deg.C) . The load of motor is proportion to mass of the gas. Hence the motor may over loaded. Care shall be taken during trial run of ID Fan. The inlet vane shall be opened to the rated current.