1. Inspection before starting the tunnel axial flow fan (key step)
1. Equipment status check:
– Confirm that the fan impeller is not blocked, the blades are not damaged, the air duct is not clogged, and the connecting bolts are tightened.
– Check if the circuit breakers and terminal blocks inside the frequency conversion start-up cabinet are loose, and ensure that the cabinet door is tightly closed without any foreign objects or water accumulation.
2. Safety preparations:
– Ensure that there are no personnel working in the operation area, the fan outlet is not blocked, and hang a warning sign “Starting in progress, be cautious of safety” (if necessary).
– Operators need to confirm that they are familiar with the location of the stop button in case of an emergency.
II. Power Supply Operation for Tunnel Axial Fan Control Cabinet
1. Turn on the main power switch:
– Locate the main power circuit breaker (the main switch) inside the cabinet. Rotate the handle from “OFF” to “ON”, and hear the “click” sound before locking it. At this point, the main power indicator light (such as “Power Indicator”) will light up.
2. Turn on the control power switch:
– Close the control circuit breaker (small circuit breaker or knob), and move it to the “ON” position. The control circuit is energized, and the operation panel buttons and display (if any) will be activated.
III. Tunnel Axial Fan Mode Settings (Choose according to requirements)
The frequency conversion start-up cabinet usually has modes such as “local manual” and “remote control”. Before starting, it is necessary to confirm the mode:
– Local Manual Mode (On-site Operation):
Switch the mode selection switch (such as the “Local/Remote” knob) to “Local” or “Manual”. At this point, you can directly control it through the on-site buttons.
– Remote Control Mode (Control by External Signal):
If you need to start it through PLC or the central control system, switch to “Remote”. The start will be triggered by an external signal (make sure the remote signal is normal before proceeding).
Start the fan
(1) Local manual startup (the most commonly used)
1. Press the “Start” button:
Press the green “Start (START)” button on the cabinet panel. The frequency converter begins to output voltage, and the motor drives the fan to start slowly (soft start with frequency conversion, the speed gradually increases from 0).
– During the start-up process, observe the display (if any): the frequency gradually increases from the initial value (such as 0 Hz), and the speed also increases synchronously, with no abnormal noise.
– If the start fails (the fault code appears on the frequency converter display panel), immediately press the “Stop” button, and check for overload, phase missing, or motor faults before trying again.
2. Confirm the initial speed:
After starting, the fan defaults to running at the initial frequency (such as 50 Hz or the preset minimum frequency), or maintains the speed before the last shutdown. You can observe the current status using a speed meter or frequency meter.
(2) Speed control operation of the tunnel axial flow fan frequency conversion control cabinet (if you need to adjust the air volume)
1. Speed Adjustment:
Press the “Acceleration (ACCEL)” button or the up arrow key. The frequency gradually increases (e.g. from 30Hz to 50Hz), the rotational speed rises, the air volume increases. Release the button to lock the current rotational speed.
2. Deceleration Adjustment:
Press the “Deceleration (DECEL)” button or the down arrow key. The frequency decreases (e.g. from 50Hz to 20Hz), the rotational speed decreases, the air volume decreases. Release and maintain the current rotational speed.
3. Note:
– Speed adjustment should be carried out slowly. The single adjustment range should not be too large (e.g. increase or decrease by 5Hz each time). Avoid fan vibration or motor overload.
– The lower limit of rotational speed is limited by the parameters of the frequency converter (usually not lower than 10-15Hz). Too low a rotational speed may cause poor heat dissipation of the motor.
When starting the mine-use counter-rotating fan, the rotation direction of the fan impeller must be consistent with the arrow on the fan housing. When two motors start simultaneously, the interval should not exceed 30 seconds. The two motors should operate at the same speed. Either one can be started and operated independently.
