Mine Hoist Signal Equipment

Main technologies and related requirements of the hoist electrical control system and signal control system include the technical requirements for the design, selection, configuration, structure, performance, manufacturing, installation guidance, testing, commissioning, trial operation, training, technical services, maintenance, and quality assurance of the software system, equipment, and their accessories.

Communication Between the Main Control System and the Signal System

The main controller and monitoring controller communicate via dedicated cables within the same cabinet, where cable and fiber speeds are nearly identical. The main control and signal systems use single-mode, single-fiber communication, offering wide bandwidth, low loss, long distance, low error rate, and strong anti-interference performance.

This improves speed, accuracy, and real-time monitoring of underground safety doors, platforms, and car stoppers. Faults can be quickly located and addressed (emergency stop, deceleration, or lockout after stopping), enhancing overall stability and safety. Lightning and electromagnetic interference are mitigated with optical fiber fieldbus communication and surge protection at signal stations.

Equipment requirements: Use industrial-grade switches, transceivers, and fiber devices. Fiber must be 24-core, single-mode, flame-retardant, and meet vertical shaft installation standards.

Point Marking Process

The signaling process is divided into: shaft mouth signals, mid-level signals, and emergency signals. Mid-level signals are further divided into direct signals and relay signals.

Shaft mouth signal: Only the shaft mouth has control authority; mid-levels cannot send signals. Mid-levels retain emergency stop and deceleration stop authority to halt the container at that level for operating equipment (oil pump, safety door, platform, car stopper, pusher, etc.). Mid-level direct signal: The mid-level where the hoisting container is located has control authority; all other levels, including the shaft mouth,have no control.

Mid-level relay signal: Both the container’s mid-level and the shaft mouth have control authority, but final authority rests at the shaft mouth. The mid-level signal must be relayed through the shaft mouth before the main control system receives the start signal.

Emergency signal: Sent by hardware bell pulse directly to the main control system. Used only when the signal control system fails and cannot  be quickly restored. Not for long-term use; for emergencies only.

Main Control System Overview

The operation console is designed as an integrated structure, which becomes a three-part structure when the system includes upper-level monitoring. The console surface is equipped with instruments, indicator lights,buttons and switches, brake handles, and main command handles, forming the display and control platform of the electrical control system. The instruments display key parameters including control power voltage,operating speed, set speed, main circuit current, brake current, and brake oil pressure. Indicator lights show the status of external relay hardware safety circuits, PLC software safety circuits, system equipment such as hydraulic and lubrication stations, and control modes including manual operation, maintenance, and rope adjustment. They also indicate clutch engagement for dual drums, hoisting, lowering, deceleration points, and  minor fault conditions. Environmental temperature: High temperature:+40 ℃ Very low temperature: -15 ℃ Altitude: ≤ 2000m。

The main command switches and handles allow the operator to perform forward and reverse overwind resets, switch between rope adjustment, maintenance, manual, and semi-automatic operation, convert between normal and emergency hoisting control, select hoisting or lowering directions, reset the system after safety faults or emergency stops, and adjust the motor speed or frequency. Inside the console, multiple PLC modules are installed, mainly comprising the CPU main control module, a 10-channel digital I/O expansion module, and analog input/output modules. Signals from various control and feedback points are collected through input ports, processed, and output as control signals. The system uses two original Siemens PLCs connected via network, with the main controller being a high-performance internationally recognized PLC, ensuring powerful and reliable control. The CPU and digital modules handle signal acquisition, computation, and actuator control to implement all aspects of the hoisting process. The PLC system consists of digital I/O, analog I/O, CPU, functional, counting, and communication modules, with over 20% of I/O capacity reserved for future expansion.

Safety is ensured through redundant circuits combining PLC control elements and relays. In case of PLC failure, the system can operate at low speed for simplified start-up. Full-travel speed monitoring provides pre-alarms at 8% above the set speed and safety braking at 15% above the set speed. Overwind monitoring triggers pre-alarms at 0.3 meters and safety braking at 0.5 meters. Backup point-speed monitoring provides additional protection, and interfaces are reserved for brake shoe wear and spring fatigue protection. Interlocks are applied for handle zero position and rope adjustment, as well as logical interlocks between brake oil pumps and high-voltage line reversers. The PLC software also provides comprehensive fault protection.

The control system supports multiple operational modes. In manual mode, the operator controls the hoist below the set speed, with automatic deceleration and precise stopping under travel controller supervision. Semi-automatic operation allows the operator to complete a hoist cycle using the handle when conditions are met, with automatic direction and speed selection, acceleration, deceleration, and precise stopping. Fully automatic operation enables the hoist to follow the signal system’s direction and mid-stage commands to complete a full hoist cycle and stop automatically,also performing automatic direction and speed selection. Maintenance mode allows manual operation at 0.3–0.5 m/sfor inspection purposes. In the event of a PLC fault, emergency low-speed operation is possible at less than 1.0 m/s, complying with the Safety Regulations for Metal and Non-Metal Mines.