Wire rope electric hoists may sometimes generate noise during operation. How should this be resolved? Deyi Hoisting provides a detailed explanation below:
1. **Noise in the control circuit:** This is usually caused by a contactor malfunction—often due to poor contact, mismatched voltage ratings, or a jammed magnetic core. The faulty contactor should be inspected and repaired; if repair is not possible, it must be replaced. Once the issue is resolved, the noise should disappear.
2. **Abnormal noise from the motor:** If this occurs, stop the machine immediately to check for faults such as single-phasing (running on two phases), damaged bearings, misalignment of the coupling, or stator-rotor rubbing (where the rotor scrapes against the stator). These issues cause abnormal motor sounds:
* **Single-phasing:** The motor emits a rhythmic "humming" sound that fluctuates in intensity.
* **Damaged bearings:** A "humming" sound accompanied by a "clunking" or "clicking" noise near the bearings.
* **Misaligned coupling or stator-rotor rubbing:** The motor emits a very loud, high-pitched humming sound, sometimes accompanied by sharp, piercing noises.
3. **Abnormal noise from the hoist mechanism:** Issues such as a lack of lubricant in the gearbox or bearings, gear wear or damage, or bearing failure require immediate shutdown and inspection.
* **Excessive gear wear or damage:** Produces a loud, deep rumbling sound.
* **Damaged gearbox bearings:** Similar to motor bearing failure, this produces abnormal noise near the bearings.
* To prevent the problem from worsening, any damaged gears or bearings must be immediately removed for inspection, repair, or replacement to eliminate the fault and reduce noise levels.
