Energy Sources

Conveyor systems can be deceptively complex from a LOTO perspective due to their length and multiple drive points. All energy sources must be identified before servicing or maintenance:

  • Electrical: Drive motors (possibly multiple), variable frequency drives, sensors, and control systems
  • Pneumatic: Diverters, stops, lifts, and actuators along the conveyor path
  • Mechanical/Gravity: Gravity-fed roller sections, incline/decline sections where product weight creates stored energy

Typical Isolation Points

  1. Drive motor disconnects: Each drive zone typically has its own motor and energy isolating device. All must be isolated for full conveyor lockout.
  2. Pneumatic supply valve: Main air supply to conveyor pneumatic components. Lock the valve closed and bleed downstream pressure.
  3. Control power disconnect: Separate from motor power in many installations. Controls sensors, PLCs, and HMI systems.
  4. Gravity section stops: Mechanical blocks or pins to prevent product movement on gravity-fed sections.

Multi-Zone Considerations

Long conveyor systems often span multiple work zones. When servicing only one section, determine whether upstream and downstream sections can remain operational. Group lockout procedures may be necessary when multiple trades work on the same system simultaneously.