Project Completed: 19th of October 2018

The scope of this project included the supply and installation of a new MV cable to replace a 30 year old MV ring around the Airfield in Dublin Airport between Substation “A” and the West Substation.

The project was broken up into the following three segments. Each leg was to be upgraded on a phased bases in order to minimise disruption to the network. The three segments were as follows:

• Segment 1- Upgrade MV Cable between Substation A to Substation E
• Segment 2- Upgrade MV Cable between Substation E to the Maintenance Base Substation
• Segment 3- Upgrade MV Cables between Maintenance Base Substation to Substation W

Mainline Power completed the following as a part of the project:

Civils Works

• Provision of Traffic Management during.
• Provision of circa 3.5km trench to facilitate the MV cable installation which were direct buried in grass areas including cable protection and markers, backfilling of trench, landscaping etc.
• Provision of pit/ducts for entry into each substation including repairing the pavement after the installation
• Provision of a duct for road crossings and drainage ditches to facilitate the new MV cable including repairing of the road pavement. Note exposed drainage ditch crossing ducts shall be 225mm reinforced cast iron type.

Electrical Works

• • Supply and installation of circa 10,000m new MV cables, 3 number singles plus earth in trench, existing/new ducts.
  • Disconnection of existing MV cables from the Ring Main Unit and removal from the ducts. The decommissioned cables were excavated to at least 20m from the entrance point to the Substations and removed to avoid any future confusion.
  • Terminations of new MV cable to Ring Main Unit (6 Sets of 3 Terminations)
  • Test and commission MV cables including a:

• 1. Soak test
  2. Partial discharge test
  3. Tan Delta measurement
• Update drawings with the GPS coordinate locations of the new MV cable

At all-times one portion of the MV was required to be maintained and operational.