Case study: Medium Voltage Distribution System Upgrade

Ports

Medium Voltage Distribution System Upgrade

Customer: Port of Seattle

Project Location:Seattle, Washington

The Port of Seattle wished to improve the reliability and add redundancy to their main 15KV power distribution system. This required the addition of two new 15KV feeders from their North main substation (109 and 111) and two new 15KV feeders from their South main substation (209 and 211). The new feeders would serve both new and existing loads as well as future loads. Approximately 60% of the 18,000 linear feet of new feeders were installed in the existing Duct Bank and Manhole system, with the remaining 40% run in new conduit within existing utility tunnels and new underground Duct Banks.

The Challenge

Install the new feeders, as well as reconfigure several existing feeders, within the existing Duct Bank and Manhole system without impacting airport operations (i.e. limited or no down time). The existing Duct Bank and Manhole system being utilized also contained most of the Airports 15KV distribution system. Most of the manholes already contained large separable splices, which limited the available space for new feeders.

Just prior to the completion of the 90% document deliverables, due to capital budget availability, the project was split into two construction packages.

The Solution

Extensive field investigation of the existing 15KV distribution system including all manholes, utility tunnels and existing load terminations. Each feeder and its associated separable splices were located and detailed on the construction drawings. A detailed construction sequence was developed in coordination with detailed construction phasing included on the construction drawings.

The project being split into two separate construction packages was efficiently handled by the Harris Group design team, in close coordination with the Port, such that the overall cost associated with development of two completely separate bid packages was greatly minimized.

The Benefits

The new power center met all the Ports criteria which included safety, functionality, operation, capital budget and schedule. The upfront field investigation performed by Harris Group design team allowed the many potential construction challenges to be avoided by addressing them during design. Harris Groups level of field investigation and detailed design resulted in construction change orders below 5% as well as accurate documents for the Port to utilize for maintenance and future projects.

Ports Home » Markets » Ports » Case Studies » Medium Voltage Distribution System Upgrade
Overview Case Studies ...more White Papers Contacts	Medium Voltage Distribution System Upgrade Customer: Port of Seattle Project Location:Seattle, Washington The Port of Seattle wished to improve the reliability and add redundancy to their main 15KV power distribution system. This required the addition of two new 15KV feeders from their North main substation (109 and 111) and two new 15KV feeders from their South main substation (209 and 211). The new feeders would serve both new and existing loads as well as future loads. Approximately 60% of the 18,000 linear feet of new feeders were installed in the existing Duct Bank and Manhole system, with the remaining 40% run in new conduit within existing utility tunnels and new underground Duct Banks. The Challenge Install the new feeders, as well as reconfigure several existing feeders, within the existing Duct Bank and Manhole system without impacting airport operations (i.e. limited or no down time). The existing Duct Bank and Manhole system being utilized also contained most of the Airports 15KV distribution system. Most of the manholes already contained large separable splices, which limited the available space for new feeders. Just prior to the completion of the 90% document deliverables, due to capital budget availability, the project was split into two construction packages. The Solution Extensive field investigation of the existing 15KV distribution system including all manholes, utility tunnels and existing load terminations. Each feeder and its associated separable splices were located and detailed on the construction drawings. A detailed construction sequence was developed in coordination with detailed construction phasing included on the construction drawings. The project being split into two separate construction packages was efficiently handled by the Harris Group design team, in close coordination with the Port, such that the overall cost associated with development of two completely separate bid packages was greatly minimized. The Benefits The new power center met all the Ports criteria which included safety, functionality, operation, capital budget and schedule. The upfront field investigation performed by Harris Group design team allowed the many potential construction challenges to be avoided by addressing them during design. Harris Groups level of field investigation and detailed design resulted in construction change orders below 5% as well as accurate documents for the Port to utilize for maintenance and future projects.