Constant torque
 

Torque question

On the runway, ready to take off, the PLs up to 370lbs, the constant torque adjusted at 424.
Constant torque turned on, the torque goes up to 424 on both engines, so far quite normal.
But as soon as the plane takes off, around 200ft according to the pilot, the left engine torque goes up to: between 450 and 500 lbs. We considered the APR but as it goes up sometimes to 75 lbs....
The right engine is working OK
Any ideas considering it doesn’t happen every take-off?
I am one of the technicians working on the problem and all run-ups are normal....
Thanks for any suggestion.
Dda

Just curious, what kind of aeroplane and what type of engines?

Ram air effect? Was there a cross wind?

Don't know what type you're talking about but is there uptrim installed?

Maybe switch is shorting at a certain pressure due to airspeed.