Practical Power Plant Engineering

4Designing Plant Layout

CHAPTER MENU

• 4.1 Plant Power Distribution Routes
• 4.2 Underground Installations
  • 4.2.1 Concrete Duct Banks
  • 4.2.2 Soil Thermal Resistivity
• 4.3 Plant Electrical Rooms
• 4.4 Plant Design
  • 4.4.1 Room Numbering
  • 4.4.2 Cable Floor Openings
  • 4.4.3 Process Plant Enclosures
  • 4.4.4 NFPA Concerns for the Electrical Rooms
• 4.5 Transformer Vault Design
  • 4.5.1 NFPA Fire Guidelines
  • 4.5.2 Oil Containment
• 4.6 Plant Control Rooms
• References

4.1 Plant Power Distribution Routes

The plant layout will in principle follow the process flow from the ore body to the final product output by going through the various specific process facilities. The electrical rooms will be located close to the load centers. Small plants would typically require a single electrical room, while the larger plants would need several electrical rooms to minimize the length of cables to the loads. The plant power distribution system will bring power at 13.8 or 4.16 kV in form of overhead lines and cables to the unit substations in the electrical rooms in the process areas.

Unit substations of up to 2/3 MVA will use dry transformers placed indoors within the electrical rooms, which will also contain 480 V motor control centers (MCCs), distribution boards (DBs), and lighting panels (LPs).

An electrical engineer must be present during the initial phase of the plant layout design. The task of the engineer is to insure the electrical buildings and spaces for cable tray routing are properly laid out. The routes ...