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Precautions to Take After an Accident Stoppage of Mine Hoists

2022-07-29

　　Precautions to Follow After a Mine Hoist Accident Shutdown: If the mine hoist is running and suddenly stops due to a malfunction triggering the safety protection system, the operator should immediately report the incident to the dispatch room and then perform the following steps: Move the control handle to the power-off position, firmly engage the brake, and proceed with the appropriate actions based on the specific type of accident as outlined below.

　　Precautions to take after an emergency stop of a mine hoist:

　　The mine hoist is currently in operation. If a fault occurs and the safety protection device activates, causing the hoist to shut down abruptly, the operator should immediately report the incident to the dispatch room and then perform the following steps: - Move the control handle to the power-off position. - Fully engage the brake. - Depending on the nature of the accident, follow the appropriate procedures outlined below. - Finally, document the sequence of events, the root cause of the incident, and the corrective actions taken in both the operational logbook and the accident record book.

　　(1) If the shutdown is caused by a malfunction in the mine hoist itself, operation must be prohibited until the root cause of the failure has been identified. Once the cause is clarified, if the issue cannot yet be fully resolved but the system can be temporarily restored to operational status, continue running until the current lifting cycle is completed, then shut down again for further troubleshooting. If the operator is unable to address the fault on their own, they should immediately report the issue to the supervisor or responsible manager.

　　(2) If the mine hoist stops due to a power outage, while reporting to the dispatch center, the operator should also perform the following tasks:

　　① Immediately switch off the main power switch and set the master controller handle to the central "0" position.

　　② The working gate is set to the closed position.

　　③ Place all electrical starting devices in the start position;

　　④ Contact the distribution station and report to the supervisor.

　　⑤ Restart and power on after power is restored.

　　(3) When the mine hoist stops abruptly during operation due to sudden braking of the safety brake, the steel wire rope and its connecting devices must be inspected before resuming operation if any of the following conditions exist.

　　When the steel wire rope swings violently, and the rope speed exceeds 5 m/s (based on the position indicated by the depth gauge), or when the deceleration during braking exceeds 3.5 m/s (as determined from brake test records and observed by counting the number of drum revolutions after braking).

　　(4) If the hoisting container becomes stuck in the mine shaft, starting the hoist will cause the wire rope to loosen. In this case, the machine should be stopped immediately for troubleshooting.

　　① Since the fully loaded bin has jammed the hoisting container, causing the wire rope to slacken upon startup, please contact the relevant personnel. Until the issue is resolved, unloading coal (or gangue) from the bin outward is strictly prohibited.

　　② Since the cage is supported by the cage seat, starting the equipment may cause the wire rope to loosen. In this case, contact the signal operator immediately. Do not retract the cage seat until the issue has been resolved.

　　③ If the rope isn’t excessively loose and the wire rope hasn’t twisted, the operator should address the issue promptly by slowly reversing the machine to reel the rope back in.

　　④ If there is excessive slack in the rope, which could lead to kinks, the operator should immediately contact the wire rope inspector (or maintenance worker).

　　(5) If the mine hoist shuts down due to a failure in the safety protection circuit, it should be reported to the dispatch room, and, depending on the situation, the following actions should be taken immediately:

　　① Identify the cause of the malfunction, and if the driver is capable of handling it, immediately restore power.

　　② After identifying the cause of the fault, if immediate repair and restoration are not possible, for similar dual-line systems with independent circuits (such as over-wind protection devices), you may short-circuit one of the lines. Proceed with startup under the supervision of one person while another operates, and address the issue promptly after the current hook has been lifted to its full height.

　　③ If the speed-limiting device malfunctions and cannot be independently repaired, immediately report to the relevant authority and only resume operation after implementing effective safety measures.

　　④ If other parts of the safety protection circuit—such as open circuits, ground faults, or poor contact—experience functional failures while the protected component itself remains operational, you can short-circuit the faulty circuit or contact. After doing so, resume operation while intensifying monitoring of that specific area, and address the issue immediately after the hook has finished lifting.

　　(6) After an overwinding stop, report to the dispatch room and coordinate with the shaft signal operator. Once the maintenance electrician resets the overwinding switch, you can reverse the drive to lower the hoisting container back to the parking position, resuming normal hoisting operations.

　　(7) When the steel wire rope experiences jamming, sudden stops, or other severe tensile forces, the elevator must be immediately halted for a thorough inspection of the rope. Only after confirming that the inspection is clear can operations resume. Elevator manufacturer

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Common Faults and Troubleshooting Measures for Mine Hoist Gearboxes

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2022-07-29