Recent Projects

Western Area Power Administration, Dept. of Energy - Olinda Substation Stage 02

Description of work: Installed Government-furnished 230-kV motor-operated disconnecting switches with grounding blades.

  • Furnished and installed equipment jumpers, grounding, conduit, terminal boxes, interface panels, motor-operated disconnect switch junction boxes, insulated conductors and cables, and substation signs.
  • Furnished and installed foundations and anchor bolts for substation structures, electrical equipment, and material.
  • Performed site work, removed and reinstalled steel structures and electrical equipment.
  • Removed and disposed of electrical equipment, and materials.

Ingredion Corn Product International Inc. - Fire Restoration Substation

Description of work: Provided client with a complete package procurement and installation of 115kV- 12.47kV Substation, including but not limited to:

  • Fabricated steel, welded busing, 115kV circuit breaker, two 115kV manually operated disconnect switches, one motor operated disconnect switch, CCVT, Metering Class CITs, relay/protection panels along with A/C-D/C power panels.
  • Provided yard surfacing above and underground conduit, control cable installation and wiring.
  • Provided yard surfacing above and underground conduit, control cable installation and wiring.
  • Worked with PG&E to perform pre-parallel testing to ensure provided protections would not affect grid reliability.

Alameda County - Oakland Coliseum and ORACLE Arena Substation Replacement

Description of work: Removed and replaced 2 existing 12KV switchgear units, one feeding Oakland Coliseum and one feeding the ORACLE Arena. New switchgear consisted of:

  • 1ea. Metering Section with provisions for PG&E meters, PT’s and CT’s provided installed by PG&E.
  • 1ea. Aux section consisting of PT’s , CPT, AC and DC panels, 48v Batteries, DC Battery Charger.
  • 1ea. Breaker section each featuring 1200amp 25KA draw out breaker, 400:5 CT’s, Schweitzer 751 protection relay, Schweitzer 735 power meter, test switches, breaker control switch, indicator lights.
  • PG&E to perform pre-parallel testing to ensure provided protections would not affect grid reliability.

Central Contra Costa Sanitary District - Substation 16 Switchgear Replacement District Project

Description of Work: Replaced 2 individual outdated 4000Amp Open transition tiebreak Switchgear and Power Busway, with 2 new Arc Flash technology 4000Amp switchgears and new Busway, running to 4 existing transformers.

  • Installed 1200 Amp temporary power system to keep plant operational during construction.
  • Installed remote panels for each section of gear for maintenance operators, as well as PLC control wiring for Operations control.
  • Provided Design of Interconnect and PLC wiring and respective cabling and connections, more than control terminations.
  • Testing and Start-up. Unique features of the project.
  • Cut 108” Tall by 96” wide concrete panels into the wall to gain access into the building and perform work.
  • Replaced concrete panel openings with commercial doors for future access.

Shelter Cove Resort Improvement District 1 - 12kV Electric Underground Cable Replacement Project

Description of work: Installed Single-Phase Dead Front & Duplex Pad Mount Transformers.

  • Installed Box Pads for Pad Mounted Transformers.
  • Located existing wet and dry utilities to avoid conflicts.
  • Installation of primary, secondary cables, splices, terminations and connectors included trench, excavation, compaction, paving, and directional drilling.
  • Removed existing equipment, cable and ancillary material.
  • Replaced 12kV overhead pole lines and risers.

Barrick Western 102 Power Plant

Description of work: Removed existing 750MCM parallel 13.8kV feeders (6 in total) and replaced with new 750MCM cable and ground. Installed 18 outdoor 3M terminations and 18 indoor 3M terminations.

Dutra Materials - 5kV Overhead Distribution

Description of work: Design/Build Re-Route of 5kV Overhead line to make room for mining operations to continue.

  • Added UG Section to move line under equipment in lieu of over the equipment.
  • Split the power in the plant to two feeders to promote a smooth plant operation with minimal down time for maintenance.
  • Installed new fiber optic network to main plant so operations could be seen from one central location.

Dole Package Foods - 12kV Overhead Distribution Rehabilitation Project

Description of work: Replaced degraded overhead 12kv line along with relocation of existing pole mounted transformer.

  • Removed 2,000’ of overhead primary 4/0 ACSR replaced with 636 ACSR to allow for a loop feed system as the upgrade progresses.
  • Install and terminated underground feeder to new riser pole with new Inertia Line Boss switch.
  • Relocated pole mounted equipment as needed in the rehabilitation process.

Contra Costa Water District - Medium Voltage Wire Replacement Project

Description of work: Provided all needed material, tools, and equipment to replace three (3) 4160vac circuit conductors with ground wire in approximately 450 lineal feet conduit.

  • From Substation SC-1 Circuit Breaker 1-B to Transformer 1-B with 250MCM shelled EP 115 Mills 5KV cable.
  • Install termination kits on both ends and perform VLF testing per IEEE 400.2.
  • Removed existing wiring from conduits visually inspected buried conduit for damage.
  • Termination kits installed by our certified personnel that have been trained in medium voltage cable work.

About National High Voltage Services, Inc.

National High Voltage Services, Inc. (NHVSinc.) is a specialized High Voltage contractor with an emphasis on HV Underground Cabling Systems, Installation and Splicing, Switchgear Installation, Maintenance and Replacement. We are also a full service Substation Contractor in the areas of New Construction, Maintenance Repair and Rehabilitation.


Contact Us
(916) 476-8100