Why Is the SDF Series Tunnel Axial Flow Fan Hard to Start?

The SDF Series Tunnel Axial Flow Fan is a critical component in mining and tunneling operations, designed to provide efficient ventilation in confined spaces. However, like all mechanical equipment, it can encounter issues that may affect its performance. One common problem is difficulty starting or a low impeller speed under load. This article provides a step-by-step guide on how to troubleshoot and address the issue.

1. Power Supply Voltage is Too Low

One of the most common causes of difficulty starting or low impeller speed is an insufficient power supply. If the voltage supplied to the fan is lower than required, the motor may struggle to start or may not achieve full operational speed under load.

Solution:

Use a multimeter to measure the input voltage at the fan’s power supply terminal.

Compare the measured voltage with the fan’s rated voltage, as specified in the user manual.

If the voltage is too low, take corrective action, such as checking for issues with the power supply or voltage regulator, or contacting the power company to resolve supply issues.

2. Cage Rotor Open Welding or Breakage

Another possible cause of low impeller speed or starting issues could be a problem with the cage rotor. If the rotor has open welds or breakage in its structure, it can result in uneven rotation, excessive wear, or even complete failure of the fan.

Solution:

Inspect the cage rotor thoroughly for signs of open welds, cracks, or broken parts.

any breakage or welding failure is detected, repair the rotor by rewelding or replacing the damaged components.

Ensure that the rotor is rebalanced after repairs to avoid further damage to the fan.

3. Incorrect Winding Turns in the Motor

If the fan’s motor has been rewound incorrectly—specifically, if the number of winding turns exceeds the specified value—the fan’s motor may struggle to start, or the impeller speed could be too low under load.

Solution:

Inspect the motor’s winding and compare the number of turns with the manufacturer’s specifications.
If the number of winding turns is too high, the motor should be rewound to the correct number of turns.

Ensure that all rewinding is done carefully to avoid further issues with the motor’s performance.

Proper maintenance and troubleshooting are essential for ensuring the continued efficient operation of the SDF Series Tunnel Axial Flow Fan. By checking the power supply voltage, inspecting the rotor for damage, and ensuring correct motor winding, you can resolve many common issues related to low impeller speed and difficulty starting. Regular inspections and maintenance will help prolong the lifespan of the fan and improve its performance in the demanding conditions of tunnel ventilation.