The TT XXX T fan starts running after the external switch supplies a control signal to the LT input terminal (for example, during turning the light on). After removal of the control signal the fan continues to run within the set time (adjustable with the turn-off delay timer from 2 to 30 minutes). To adjust the fan turn-off delay time, rotate the control knob T clockwise to increase and counter-clockwise to decrease the turn-off delay time respectively (Fig. 19). Warning! The timer circuit is under mains voltage. Disconnect the fan from the power supply prior to any adjustment operations. The fan delivery set includes a specially designed plastic screwdriver for adjustment of the fan parameters.