Across
- 4. __________ cables are used to supply power to portable mining equipment.
- 7. All electrical wiring must be properly __________ to prevent short circuits.
- 11. All electrical components must meet MSHA _______ before mining usage.
- 12. Electrical enclosures must be _____-tight to prevent dust and moisture entry.
- 15. Electrical switches must be labeled for their ___________ function.
- 16. Explosion-proof enclosures must pass an __________ test to ensure safety.
- 17. The primary purpose of electrical grounding is to prevent ______ hazards.
- 18. The max. voltage allowed for battery-powered equipment in mines is_____ volts.
Down
- 1. Control circuits are designed so that equipment ______ automatically when power fails.
- 2. MSHA requires electrical equipment to undergo __________ inspections.
- 3. Power circuits must have circuit breaker protection to prevent excessive ______ flow.
- 5. To prevent accidental contact, high-voltage components must be____________.
- 6. _____________ relays are required to protect motors from overheating and damage.
- 8. The __________ of electrical equipment must display the MSHA approval number.
- 9. __________ wires must be connected to an effective ground to prevent shock hazards.
- 10. _____ motors are likely used in underground mining equipment due to high torque.
- 13. Electrical connectors used in mines must be __________ to prevent sparks.
- 14. The insulation resistance of electrical cables must be tested using a _________.
