High Voltage Connection Strategy
PoC HV mains in Grafton Road (identified by NGED)
Switchgear Schneider RN6d ring main unit, loop connected to NGED network
Metering Unit Schneider MU6d close coupled behind RN6d for tariff metering
Substation Housing GRP enclosure with separate meter compartment on NGED plinth
Cabling 2 × 300 mm² Al triplex XLPE (960 m each) from PoC to substation
Earthing Installed to NGED standard design and tested prior to energisation
ICP Scope of Works
1. Civils
- Excavate and reinstate 960 m off site trench plus final joint bays.
- Cast substation plinth and install GRP housing with collision protection.
- Working with client and architects to find the perfect location for the new substation taking into account , walls and foundations, existing gradients and underground drainage whilst ensuring that the substation was constructed in line with NGED specifications
2. Cabling & Joints
- Supply, lay and record two triplex HV cables from PoC to Yardley Wood.
- Complete straight and half breech joints for energisation.
- Supply and install a dual 11kV circuit along with a full suite of as built engineering drawings
3. Plant Installation
- Position RN6d + MU6d within GRP enclosure.
- Terminate HV loops onto RN6d and customer supplied transformer tails.
- Install and terminate multicore metering cable into adjacent switch room.
4. Testing & Commissioning
- Perform insulation, pressure and earth resistance tests.
- Submit as built drawings and test certificates to NGED.
5. Project Management & Compliance
- Ensure all design, materials and workmanship meet NGED codes, BS EN and IEC standards.
- Liaise with NGED through energisation, hand over and adoption of contestable assets.
Ownership & Adoption
- Customer retains: GRP enclosure, transformer, LV switchboard and routine maintenance duties.
- NGED adopts: RN6d, MU6d, HV terminations and both 300 mm² triplex cables upon successful commissioning.
Project Highlights
- 4 MVA Secured – Adequate headroom for fast bus chargers plus future expansion.
- Minimal Disruption – Off site trenching sequenced to maintain depot and public road access.
- Single Lift Substation – Factory assembled GRP unit shortened on site build time.
- Regulatory Compliance – All works executed under NGED specifications; no unapproved equipment installed.
- Safety First – Substation fenced to prevent vehicle impact and ensure pedestrian safety.
Outcome
Yardley Wood now has a robust, NGED backed HV supply ready for rapid EV charger deployment. The project demonstrates how coordinated DNO, ICP and customer collaboration can accelerate large scale transport electrification while ensuring long term asset reliability and compliance.
Need Similar Support?
Whether you’re planning a single depot or a region wide fleet upgrade, our engineers can deliver complete HV solutions—design, civils, plant, testing and hand over—fully aligned with DNO / IDNO standards.
