H‑Infinity

Detailed design is where the concept becomes reality. Our primary and secondary design team produces construction-ready drawings, schematics, and specifications that define every cable, connection, and component — ensuring the electrical system is built exactly as engineered, on time and within budget.

01What is Detailed Design?

Detailed design encompasses all engineering deliverables required for procurement, construction, and commissioning. It is divided into two main areas:

Primary Design

Covers all high-power electrical equipment and connections — switchgear, transformers, cables, busbars, earthing conductors, and lightning protection. Primary drawings show the actual power flow paths.

Secondary Design

Covers control, protection, and instrumentation circuits — relay wiring, control schematics, terminal diagrams, and cable schedules. Secondary drawings show how the system is monitored and controlled.

02Why Detailed Design Matters

Incomplete or inaccurate detailed design is the leading cause of construction delays and cost overruns:

▸Construction Delays — Missing cable schedules, incorrect wire numbers, or incomplete terminal diagrams cause field confusion and work stoppages.
▸Procurement Errors — Inaccurate equipment specifications lead to wrong orders, returns, and project schedule slips.
▸Safety Risks — Poorly detailed secondary circuits can result in miswired protection schemes that fail to operate during faults.
▸Commissioning Issues — Incomplete schematics make loop testing and functional verification difficult or impossible.

03Our Approach

We use industry-standard CAD and relay setting tools to produce detailed design deliverables in formats compatible with your EPC contractors:

1. Primary Design Development

Produce detailed SLDs, layout drawings, cable tray and conduit schedules, busbar sizing calculations, and foundation drawings for major equipment.

2. Secondary Schematic Design

Develop control schematics, relay wiring diagrams, terminal block diagrams, and I/O schedules for all protection and control functions.

3. Cable Engineering

Calculate cable sizes, produce cable schedules with routing information, and prepare cable tray and ducting layouts.

4. Coordination & Review

Conduct design review sessions with clients, contractors, and equipment manufacturers to verify completeness and accuracy.

04Scope of Detailed Design

Our detailed design deliverables cover every aspect of electrical engineering:

▸Primary Drawings — Detailed SLDs, equipment layouts, foundation drawings, cable tray schedules, and busbar calculations.
▸Secondary Drawings — Control schematics, relay wiring diagrams, terminal block diagrams, panel drawings, and I/O schedules.
▸Cable Engineering — Cable sizing calculations, cable schedules with routing, and ducting/tray layouts.
▸Technical Specifications — Detailed specs for all equipment and materials, including performance requirements and testing criteria.
▸Bills of Quantities — Detailed BOQs for procurement and tendering purposes.

05Standards & Compliance

✓IEC 60439 — Low-Voltage Switchgear

✓IEC 61850 — Communication for SCADA

✓IEEE C37.100 — Substation Protection

✓IEC 61974 — Cable Tray Systems

06Why H-Infinity

We've produced detailed design packages for over 200 substations and power systems across the GCC, Africa, and Asia. Our drawings are known for their clarity and completeness — contractors can build directly from them without needing to request clarifications or RFIs. We use AutoCAD Electrical and Eplan for primary and secondary designs, with full integration to our protection and cable sizing tools.

Detailed Primary & Secondary Design