Underground Electrical & Site Infrastructure

Electrical underground often happens during some of the earliest phases of construction.

The scope may include:

• Utility service conduits

• Main electrical feeders

• Transformer pathways

• Site-lighting conduits

• Equipment feeds

• Building-to-building feeders

• Communications pathways where included

• Grounding infrastructure

• Pull boxes

• Stub-ups

Once slabs, sidewalks, parking lots, and landscaping are installed, correcting a missing underground pathway becomes significantly more expensive.

Commercial electrical services often require underground pathways between the utility infrastructure and the building's service equipment.

Depending on the project, that can include:

• Utility transformer conduits

• Service entrance conduits

• Metering pathways

• Utility pull sections

• Spare conduits

• Communication or utility pathways where required

OTC coordinates these installations with the serving utility and approved project requirements.

Utility standards matter because the utility ultimately determines what it will accept before permanent service is energized.

Ground-up electrical work may require trenching and excavation for:

• Utility service

• Electrical feeders

• Site lighting

• Transformers

• Detached structures

• Equipment

• Site electrical systems

Unlike typical interior remodel work, trenching and underground electrical installation can be included as part of OTC's ground-up electrical scope when required by the project.

The trench needs to be coordinated around:

• Other utilities

• Civil grading

• Building foundations

• Site access

• Required depths

• Conduit spacing

• Future paving and concrete

Planning the underground routes before excavation helps prevent conflicts in the field.

Larger commercial projects can require substantial underground conduit systems.

A conduit bank may contain pathways for:

• Utility service conductors

• Main feeders

• Parallel feeder sets

• Site distribution

• Future electrical systems

Large electrical services may require multiple conduits running together between the utility source, transformer, service equipment, or other major distribution points.

These systems need to be planned around:

• Conduit size

• Quantity

• Spacing

• Bends

• Pull distance

• Equipment entry points

• Future conductor installation

The underground pathway should be designed with the eventual wire pull in mind.

Ground-up projects may require site infrastructure for utility-owned or customer-owned transformers.

Depending on the design, that can involve:

• Transformer pad coordination

• Primary or utility pathways

• Secondary conduits

• Grounding

• Equipment clearances

• Bollards or physical protection where required

• Access for utility or maintenance personnel

Transformer location affects both the site plan and electrical distribution.

OTC coordinates the electrical infrastructure with the engineered plans and utility requirements before the surrounding site is completed.

Long underground electrical runs may require pull boxes or other accessible points.

These can help with:

• Long conductor pulls

• Changes in direction

• Large feeder installations

• Future maintenance

• Site distribution

Pull-box placement should consider both electrical requirements and the finished property.

A box located poorly can interfere with:

• Traffic

• Sidewalks

• Landscaping

• Drainage

• Future development

OTC coordinates locations before the site finishes are installed.

Parking lot and exterior lighting usually begins underground.

OTC can install infrastructure for:

• Parking lot pole lights

• Walkway lighting

• Monument or sign power

• Building exterior lighting

• Landscape-related electrical systems where included

That may involve:

• Underground conduit

• Pole-base pathways

• Junction boxes

• Lighting circuits

• Control wiring

• Grounding

The underground layout should follow the final site-lighting design so circuits are available where each fixture will be installed.

Not every electrical load is located inside the building.

Commercial projects may require underground power for:

• Pumps

• Gates

• Site equipment

• Detached structures

• Mechanical equipment

• Exterior receptacles

• Specialty systems

• Future equipment

OTC coordinates these pathways during underground construction rather than waiting until the equipment is installed and discovering there is no practical route to reach it.

A conduit can be installed perfectly underground and still create a problem if the stub-up is in the wrong location.

OTC coordinates underground terminations with:

• Electrical rooms

• Equipment pads

• Walls

• Panels

• Switchgear

• Transformers

• Site equipment

Field layout matters because equipment dimensions and final locations can affect exactly where the underground conduit needs to emerge.

A few inches can matter when large conduit banks need to enter switchgear or other major equipment.

Underground electrical work intersects with:

• Foundations

• Footings

• Structural systems

• Plumbing

• Fire service

• Civil utilities

• Storm drainage

• Gas

• Communications

• Concrete

• Paving

These systems compete for many of the same underground spaces.

OTC coordinates the electrical pathways with the project team before concrete placement whenever possible.

Fixing a conflict on a drawing or during layout is significantly easier than fixing it after the slab is poured.

Commercial sites with multiple buildings may require underground electrical distribution between structures.

That may include feeders serving:

• Additional buildings

• Tenant spaces

• Storage buildings

• Maintenance facilities

• Site equipment

OTC coordinates conductor size, conduit, distribution equipment, voltage, distance, and grounding around the engineered design.

Longer site runs may also affect conductor sizing and voltage-drop considerations.

Underground construction is one of the best opportunities to prepare for reasonable future electrical growth.

Where the project supports it, spare conduit can provide a future pathway for:

• Additional electrical service

• New equipment

• Site expansion

• Additional lighting

• Future buildings

• Communications

Installing an empty conduit while a trench is already open can be dramatically easier than cutting through a completed property later.

Spare infrastructure should still be planned intentionally rather than added without a likely future use.

Once underground conduit is installed, it still has to survive the rest of the construction project.

OTC protects and verifies underground systems against conditions such as:

• Crushed conduit

• Broken stub-ups

• Concrete intrusion

• Dirt or debris

• Water

• Damage from heavy equipment

• Other trades working around the pathways

A damaged underground raceway can create a major problem when conductors are ready to be installed months later.

Before underground electrical work is permanently covered, applicable portions of the installation should be verified.

That can include:

• Conduit routes

• Stub-up locations

• Conduit quantity

• Conduit size

• Pull-box locations

• Equipment pathways

• Grounding

• Required inspections

Photos and documentation can also be valuable because once the trench is backfilled, much of the installation is no longer visible.

A complete underground electrical and site-infrastructure scope may include:

• Utility coordination

• Trenching and excavation

• Service conduits

• Large conduit banks

• Transformer infrastructure

• Pull boxes

• Main feeder pathways

• Building-to-building pathways

• Site-lighting infrastructure

• Equipment power pathways

• Grounding

• Spare conduits

• Stub-ups

• Backfill coordination

• Pre-cover verification

OTC coordinates the underground electrical work so the infrastructure required later in the project is already where it needs to be.