Underground Distribution Engineering Services
Draftech delivers duct bank, vault, pad-site and cable design for new residential and commercial distribution. One in-house engineering team coordinates the package against the same civil plan before issue for construction.
Underground distribution engineering services for new development
Draftech's underground distribution engineering services bring electric duct banks, equipment sites, cable selections and service layouts into one construction-ready package. Engineering is 100% in-house. Your utility or project team has a single point of accountability for that package.
The deliverables include:
- Duct bank and conduit routing.
- Vault, handhole and pad-mount site layouts.
- Cable sizing and selection with calculations.
- Trench cross-section and separation details.
- Service layout.
- Issued construction package.
A transformer pad drawn inside a proposed easement can fall outside the recorded easement when the final plat changes. If that discrepancy survives design review, the owner may face a pad relocation after concrete is placed. A cable selected from an early loop length can need replacement when the voltage drop over the final, longer route exceeds the utility's criterion. Because the same engineers locate the pads, route the duct bank and size the cable against the governing civil plan, a plat change is caught on the drawings before issue instead of after the pad is set or the cable is pulled.
We work with utilities and cooperatives extending underground service into new subdivisions and commercial sites, and with EPCs and general contractors delivering those developments. The scope fits subdivisions, planned developments, and new commercial or industrial service where underground distribution is the utility's standard or the developer's requirement. It is part of Draftech's electric utility engineering practice.
Establish the civil plan and service requirements
The starting point is an agreed design basis: the civil plat or site plan, utility underground standards, your load information and intended service requirements. We identify which plan revision governs the work and which inputs remain preliminary.
To scope the engagement, provide:
- The current civil plat or commercial site plan, including its revision status.
- Recorded easement information, property boundaries and proposed equipment areas.
- Utility underground standards and requirements for cable, conduit and equipment arrangements.
- Owner-supplied loads, proposed service points and the intended distribution connection.
- Known development phases, owner review requirements and outstanding civil decisions.
We review the information together so an unresolved service point does not quietly become a fixed cable endpoint. For EPC and general-contractor clients, the utility's requirements remain the engineering basis. The developer's preferred layout and the utility's accepted arrangement must agree before the affected design can be completed.
Electric duct bank and conduit routing design
As part of our ductbank design engineering services for electric distribution, we develop the duct bank arrangement and conduit routing alongside the cable requirements and proposed structure locations. The drawings locate the route within the subdivision or commercial site and show how it connects the distribution equipment and service areas.
We size the duct bank from the final electric layout, because an early development plan may not provide the duct count or configuration the final layout needs. We verify the proposed duct bank against the current service configuration, cable selections and utility requirements. That review connects pathway decisions to the electric design instead of leaving an earlier section detail attached to a revised route.
Trench cross-sections show the duct configuration, depth of cover and separation from other facilities. Where other utilities run nearby, we coordinate the electric layout against the available civil information and show the separations required by the utility's standards and the NESC.
Vault, handhole and pad-mount site layouts
Vault and handhole locations develop with the conduit route and cable arrangement. Pad-mount transformer and switchgear sites develop with the service layout, property boundaries and easement information. Our engineers check those relationships together so a change to a structure location reaches the connected portions of the design.
We compare the proposed site with the supplied easement limits and the utility's clearance and access requirements. A lot-line adjustment can require another location review even when the equipment footprint itself stays unchanged.
The equipment site also establishes cable endpoints. Draftech carries the location decision back into the route and service drawings, then verifies the affected cable selection before the package advances.
Cable sizing against the actual proposed route
Draftech selects conductor and insulation type and performs ampacity and voltage-drop calculations using the utility's design criteria and owner-supplied load information. The calculation basis follows the proposed cable route, including the loop length shown in the current design. Cable selection and duct bank arrangement are reviewed together, because the number of circuits in the bank and their spacing affect mutual heating and therefore ampacity.
If loads are incomplete or inconsistent with the service requirements, we identify the missing input for resolution. The package records the basis used so the utility reviewer can connect a cable selection to the intended service and route.
We recalculate ampacity and voltage drop for the revised design rather than carrying forward a selection simply because it appeared on the previous drawing. This keeps a civil revision from leaving an unsupported cable designation in the construction package.
Residential and commercial service layouts
Our URD design engineering services coordinate underground residential distribution for the subdivision as a whole. Lot service points, transformer sites and the proposed loop need to follow the same plat. A revised lot arrangement can affect more than the nearest service: it can move an equipment site or change the route feeding another part of the development.
For commercial and industrial sites, underground electric distribution design follows the service requirements and the current site plan. We establish the utility service limits and equipment locations with the project team, then reflect those decisions in the conduit and cable design. Defining the handoff gives the utility and the site's other designers a common endpoint for their respective drawings.
Carry revisions through internal QA
Draftech reviews civil revisions through the affected duct bank sections, vault and handhole locations, pad sites, service points and cable calculations. We also confirm whether the revised arrangement still satisfies the utility's required clearances and separations.
Our QA review confirms each of these before the package issues for construction:
- Route and structure locations use the governing civil plan revision.
- Pad sites agree with supplied easement limits and required clearances.
- Cable selections match the load inputs, route lengths and proposed arrangement used in the calculations.
- Trench cross-sections and separation details agree with the plan views.
- Resolved review comments reach every affected drawing and calculation.
Your reviewer can follow a design decision from its location on the plan to its supporting calculation.
Define the feeder interfaces and delivery scope
Where the underground feeder leaves a station, we establish the boundary with distribution substation design so both packages identify the same connection. For a project with separate overhead segments, overhead distribution design covers that counterpart. Conversion of an existing overhead line belongs to overhead-to-underground conversion engineering.
You can engage Draftech for the engineering package alone. When the owner wants the new distribution design built, we offer full turnkey construction for power distribution through Draftech-managed crews under our QA/QC and safety program. When another contractor builds the project, Draftech offers construction management and inspection of that contractor's power build.
Underground Distribution Engineering Services FAQ
What does the underground distribution design package include?
The package includes electric duct bank and conduit routing, vault and handhole locations, pad-mount site layouts, cable sizing and selection, service layout, and trench cross-section and separation details. The coordinated package receives internal QA before issue for construction.
Can design start before the final plat is available?
Yes, preliminary information can support scope definition and early layout coordination. We identify the assumptions that depend on the final civil plan and supplied easement records. Those inputs must be resolved for the affected design before construction issue.
Can Draftech collect site conditions the civil plan does not show?
Yes. Our field survey team can capture the existing equipment at the tie-in point and the surface features along the proposed route. The design then places pads, duct banks and separations against conditions verified in the field, not only against the civil drawings.
Who supplies the loads used for cable sizing?
The owner provides the load information for cable sizing. Draftech uses those loads with the utility's design criteria to select cable for the proposed route. We confirm those criteria and the utility's review requirements at the start of the engagement.
Start with your current site plan
Send the civil plat or site plan, utility standards, available easement records and service loads. Identify the planned development limits and any civil decisions still pending. Draftech will define the underground distribution design scope and the information needed to complete the construction package.
Contact Draftech about your underground distribution projectinfo@draftech.com | 305-306-7407 | Miami Lakes, FL