Field Electrical Installation and In-Plant Power Distribution

Field electrical installation is the layer through which power prepared in the panels reaches the machines. Mistakes made here are invisible at the panel but show up throughout production: voltage drop, interference-driven automation faults and cable routes that cannot be traced during maintenance. Contech builds in-plant power distribution to suit both the design and the conditions on site.

Installation begins with route planning. Cable trays and ladders are positioned with the machine layout and likely future lines in mind; leaving at least thirty per cent spare capacity in trays avoids pulling new tray runs for later additions. Routes avoid hot lines, steam piping and areas exposed to mechanical impact. Separating power, control and communication cables is the most critical rule of this work. A motor supply cable and a sensor signal cable pulled side by side on the same tray produce intermittent faults on the automation side that are extremely hard to trace. Those cables run on separate trays, or with sufficient distance and a metal divider between them; where they must cross, they cross at right angles. Cable sizes follow the values calculated in the design. On long runs voltage drop is decisive; a cable selected on current carrying capacity alone leaves the motor at the far end running under-voltage and eventually damages its windings. Where busbar systems are chosen, positioning tap-off points around the machine layout determines both cable cost and the flexibility of later changes. The earthing network is built to a single design across the plant. Machine frames, panel chassis and cable trays are bonded to an equipotential bar; earthing done piecemeal creates potential differences and causes both safety and signal quality problems. When installation is complete, the cable schedule and route plan are handed to the plant; without that document every subsequent intervention starts with tracing cables.