Knowledge!Precautions for commissioning explosion-proof fans

1. Explosion-proof fan starting problem.

The explosion-proof fan can be started at full pressure or at reduced pressure. However, we need to pay special attention when choosing what kind of startup method. When starting at full voltage, the voltage must be five to seven times the rated current. When the voltage reduction is activated, the voltage squared must be proportional to the torque scale.
In both cases, reduced voltage starting is necessary. First, when the capacity of the power supply grid is insufficient, step-down start is used; second, when the power is above 11kW, it is suitable for step-down start.

2. Regarding the issue of test run.

When the explosion-proof fan is trial run, make sure that it is not operated by one person, but at least two people complete the trial run. One person is used to control the power supply, and one person always monitors the operation of the explosion-proof fan in real time. If an abnormality is discovered, the first thing to do is to stop the explosion-proof fan immediately and then proceed to the next debugging stage.

First, the steering of the impeller. What needs to be done is to observe how the explosion-proof fan impeller rotates and whether the direction is correct;

Secondly, current. When the explosion-proof fan is in normal trial operation, observe the current and check whether the operating current maintains a stable balance and whether these currents are much greater than the rated current.

Regardless of whether it is current or steering, if there is any abnormality, the trial operation of the explosion-proof fan must be stopped and necessary inspections must be made.
Finally, let the explosion-proof fan run normally and observe the situation. After running for five minutes, stop the explosion-proof fan to see if there are any abnormalities. If there are no abnormal conditions, the explosion-proof fan can operate normally and proceed to the next step.

3. Precautions during trial operation of explosion-proof fans.

There is another note during the trial operation of the explosion-proof fan. Especially when the two-speed fan is tried, it must be started at low speed first to determine the direction of rotation of the impeller to see if there is any problem with the direction of rotation. When starting at high speed, you must wait until the explosion-proof fan stops. If you rush to start, the impeller will rotate in the wrong direction during high-speed rotation, and the explosion-proof fan switch will trip, causing unnecessary damage to the motor in severe cases.

4. Explosion-proof fan input power supply problem.

When the explosion-proof fan can run normally, all you need to do is check the input power of the explosion-proof fan to see if it is normal. Similarly, the input power supply of the explosion-proof fan should be within the control range of the rated current and shall not be higher than the rated current. Of course, if the input current of the explosion-proof fan exceeds the rated current and continues to operate normally, you need to check the voltage of the explosion-proof motor to see if the voltage of the explosion-proof motor is normal.

5. Regarding the problem of the fan box.

Regarding the power of the motor, it should be noted that it is not the motor power of the explosion-proof fan required when opening all air outlets, but the mechanical loss and due reserve of the motor of the explosion-proof fan under certain working conditions. For example, the air outlet of the explosion-proof fan does not add other resistance from the outside world, or the air outlet is not connected to the pipe, so the explosion-proof fan actually runs dry, which can easily cause the motor of the explosion-proof fan to burn out. For safety reasons, workers need to add valves to the inlet pipe or outlet of the explosion-proof fan. The valve should be closed when the fan starts, and the valve should be slowly opened during normal operation of the explosion-proof fan until the working conditions are met. Of course, during this period, it is necessary to always observe whether the current of the explosion-proof fan exceeds the specified value. If the specified value is exceeded, staff need to formulate solutions in time to prepare for future problems.