Cable tray installation in coal-fired power plants

Cable tray systems in coal-fired power plants provide organized, safe, and reliable support for power, control, and instrumentation cables, ensuring efficient operation and maintenance.

Design Considerations

Cable trays in coal-fired power plants are used for MV and LV power, control, instrumentation, and special cables. They are typically pre-fabricated ladder-type trays made of hot-dip galvanized steel or fiber-reinforced plastic (FRP) for corrosion resistance, especially in areas like battery rooms or chemical houses. Trays must be strong enough to limit deflection under full load and maintain a minimum vertical clearance of 400 mm between adjacent trays.

High-voltage cables are placed on the top-most trays, with lower voltage cables arranged below in descending order.

Material Selection

Steel trays: Hot-dip galvanized with a minimum coating thickness of 75 microns or 610 gm/m² for corrosion protection.

FR

P trays: Used in highly corrosive environments. Epoxy-coated trays: Suitable for battery rooms or chemical exposure areas. Accessories: Include coupler plates, clamps, hangers, elbows, tees, reducers, and covers to ensure proper alignment and support.

Installation Practices

Planning and Layout: Review approved shop drawings to determine tray routes, lengths, and locations. Trays generally run parallel to walls and electrical panels. Support and Spacing: Horizontal trays: Supported every 2000 mm.

Vertical trays: Supported every 1000 mm in risers or shafts. Cantilever brackets are used where necessary. Cable Securing: Cables are clamped or tied to tray rungs at intervals of 1500 mm horizontally and 900 mm vertically.

Rung and Side Dimensions: Typical rung spacing is 250 mm with side runners of 100 mm. Handling and Storage: Trays should be stored horizontally on flat surfaces with timber supports at 1-meter intervals, protected from moisture and sunlight. Installation Safety: Only competent personnel familiar with electrical installation standards should perform the work.

Trays are not to be used as walkways or ladders.

Operational Benefits

Properly installed cable trays provide organized and accessible cable management, reduce the risk of damage, and enhance safety and maintenance efficiency. They also support reliable, uninterrupted power generation by ensuring cables are properly routed and protected. Standards and GuidelinesBS EN 61537: For cable ladder and tray systems.

B

S 6946: For channel support systems. Installation should follow manufacturer specifications and tested system components to ensure safety and reliability. By adhering to these design, material, and installation practices, coal-fired power plants can maintain a robust cable management system that supports operational efficiency, safety, and long-term reliability.