Enhancing Conveyor Safety: Importance and Maintenance of Emergency Pull-Rope Switches
To ensure personnel safety during emergencies, all conveyor belts must be equipped with 'pull-rope' emergency switches. These safety switches should be conveniently mounted along conveyor catwalks and pathways, covering the entire accessible length of the conveyor belt. Depending on the conveyor's design, this may extend from the walkway length to the entire belt span.
In both scenarios, emergency switches should be positioned on both sides of the belt and directly integrated into the power system. In case of emergency, pulling the rope will interrupt the conveyor's power, halting the belt.
In 1995, the U.S. Mine Safety and Health Administration conducted a study of 1100 conveyor systems, revealing a 2 percent failure rate for emergency stop switches. Following this study, MSHA issued a warning to mine operators, identifying five primary issues:
- Spillage around the switch hindering deactivation of the conveyor.
- Broken or excessively slack pull cords.
- Frozen pivot bearings at the switch shaft entry point.
- Malfunctioning electrical switches within the enclosure.
- Incorrect wiring of switch or control circuits.
These concerns can be mitigated through regular monthly maintenance and testing drills, ensuring timely troubleshooting.