Professional Answer:

A proper 11kV underground cable laying procedure is crucial for the safety and longevity of the power network. At Ningbo Changshi, we follow a meticulous process that adheres to international standards.

The procedure can be broken down into these key stages:

1. Route Planning and Trenching: A detailed site survey is conducted to identify the best route, avoiding existing utilities. The trench is then excavated to the required depth, which typically ranges from 750 mm to 1200 mm depending on the location (e.g., footpaths vs. roads).

2. Trench Preparation: The bottom of the trench is prepared with a layer of sifted sand or fine soil (bedding) to protect the cable from sharp objects. This also ensures good thermal dissipation.

3. cable laying: The 11kV cables are carefully unwound from the cable drum using specialized equipment like cable drum jacks, Cable Pulling Winches, and underground-Cable-Laying-Equipment-and-Tools.html target='_blank'>cable rollers. These tools are essential to avoid kinks and exceeding the minimum bending radius of the cable, which can cause damage to the insulation.

4. Protection and Backfilling: The laid cables are covered with another layer of sand, followed by mechanical protection such as concrete slabs or cable tiles. A bright warning tape is then placed above the protection layer to alert future excavators. The trench is then backfilled and compacted in layers to prevent subsidence.