**Initial Startup and Test Run**
To start the ventilation fan, the interlocked air dampers must be opened and other relevant dampers set to their required positions in accordance with the commissioning specifications. For the initial startup, use the local control box in "jog" mode: press the start button and immediately press the stop button to check for any abnormal sounds or vibrations during startup. After stopping and allowing the air pressure to dissipate, open the fan chamber door to verify the rotation direction and ensure there is no friction or other irregularities involving the rotating parts and bearings before proceeding with a full startup. Once the fan is running at normal speed, check for normal vibration levels and verify that the motor bearing temperature, power, voltage, and current are within normal ranges. If the current exceeds the motor's rated value, or if there is a rise in bearing temperature or signs of severe impact or vibration, shut down the fan immediately to inspect and rectify the fault. Bearing temperatures are monitored via the transmission assembly and motor bearing temperature alarm systems; generally, the rise in motor surface temperature should not exceed 80°C, and the rise in bearing temperature should not exceed 40°C. Continue commissioning only after the fan has operated normally for five minutes without issues.
**Data Testing**
Commissioning the tunnel ventilation fan requires testing parameters such as airflow volume, motor winding and ground insulation resistance, bearing temperature, rotational speed, air pressure, operating current, noise levels, and air velocity. Air velocity at the inlet and outlet is measured using an anemometer attached to a long pole; air pressure testing is conducted once the fan is operating normally. A tachometer is used to measure the actual rotational speed. Forward and reverse rotation tests are performed using three-phase current; operating current values-including starting current and steady-state running current-are read from the control cabinet in the environmental control room. After the fan stops following forward rotation, wait 30 seconds before starting the motor in reverse; this involves reversing the power supply connections to test the starting current and duration for reverse operation. Regarding the operating temperature of the motor bearings, after the fan has run continuously at rated speed for two hours, the temperature of the motor's rolling bearings must be below 80°C, and the temperature of the sliding bearings must be below 70°C. After the fan has operated normally for eight hours and is then shut down, the winding temperature of the fan motor is to be measured using the resistance method.