Generic case study. We do not name the operator, the fleet or the address — the value is the design approach, the load management strategy and the way the OZEV grant claim was put together.
The brief
A Somerset commercial fleet operator running a mixed van and car fleet from a single yard wanted to electrify six bays for overnight depot charging. The existing supply was a single-phase 100 A head with capacity already committed to workshop, lighting and office loads. The brief: deliver six dedicated 22 kW charge points, fully grant-claimed, without forcing a DNO supply upgrade if it could be avoided through smart load management.
What we did
- Site survey + load study. Measured existing peak demand over a working week, identified spare capacity windows overnight, modelled a 6-charger duty cycle against it.
- 3-phase supply upgrade. Liaised with the DNO for a 3-phase 100 A per phase head — cheaper and faster than a single-phase capacity uplift, and unlocks 22 kW per bay rather than 7.4 kW.
- Sub-main distribution. Dedicated EV TP&N distribution board with per-charger Type A RCBO protection (every EV final circuit Type A — never Type B) per BS 7671 and OZEV requirements.
- Dynamic load management (DLM). Installed a CT-clamp load monitor on the incomer; charge points throttle dynamically as building load fluctuates so the head is never tripped. Total simultaneous charging capped to available headroom.
- Cable routing. SWA in dedicated trefoil-spaced trays from the EV board to the bay backplate. Bollard protection on every charger pedestal.
- OZEV WCS grant claim. 6 sockets × £350 = £2,100 against the install, claimed through the Workplace Charging Scheme on the operator's behalf as their authorised installer.
- Commissioning, labelling and handover paperwork. Per-charger commissioning report, OCPP back-end set up against the operator's tariff, full BS 7671 certification, Part P notification through NAPIT.
Why dynamic load management
A six-bay 22 kW install is 132 kW of demand if everything ran flat-out simultaneously. No commercial yard with workshop, compressors, office HVAC and lighting has that headroom. Three options:
- Pay for a DNO uplift. Months of waiting, four-figure connection costs, sometimes five-figure if a transformer move is involved.
- Cap each charger at a static low. Wastes the asset — the 22 kW capability is there, you just can't use it.
- Dynamic load management. CT clamps on the incomer feed live load data to the EV controller. Chargers ramp up overnight when the rest of the building is quiet, ramp down during workshop peak, never breach the agreed supply ceiling.
Option 3 is the standard play for any commercial install where the existing supply is sized for the existing building. Detail in EV chargers.
The kit
| Component | Spec |
|---|---|
| Charge points | 6 × Hypervolt Home 3.0 Pro — 22 kW 3-phase, OCPP 1.6, dynamic LM-ready |
| Supply | 3-phase 100 A per phase, DNO-upgraded |
| EV distribution | TP&N board, per-charger 32 A Type A RCBO + DC fault protection |
| Load management | CT-clamp dynamic load monitor on incomer, building-aware throttling |
| Sub-main | SWA trefoil run, bollard-protected pedestals |
| Earthing | PEN fault detection per OZEV requirements, no earth rod required |
| Back-office | Hypervolt cloud / OCPP, fleet billing & reports |
Four-day install sequence
- Day 1 — DNO supply switch. Cut-over to 3-phase head, temporary supply maintained for the workshop.
- Day 2 — EV sub-main + board. SWA trayed in, TP&N EV board landed, RCBO per circuit.
- Day 3 — Pedestals, chargers, bollards. Six pedestals dug in and concreted, chargers fitted, bollards set.
- Day 4 — Commissioning, DLM tuning, handover. CT clamps fitted, load profile tuned over a working morning, BS 7671 cert issued, OZEV claim filed.
Certification & paperwork
- BS 7671 Electrical Installation Certificate — per-charger circuit, every reading logged, NAPIT-format
- Part P Building Regulations Compliance Certificate — NAPIT-notified to local building control
- OZEV Workplace Charging Scheme grant claim — submitted on operator's behalf as their authorised installer
- Per-charger commissioning report with manufacturer firmware version, serial, OCPP back-office record
- O&M pack — load management policy, isolation procedure, fault diagnostic guide
- VAT invoice — itemised, VAT @ 20%, OZEV grant credited as a discrete line
Why this approach. Most commercial fleet charging jobs fail at the design stage, not the install stage. Get the load study right, pick chargers that genuinely talk OCPP, plan the DLM strategy before quoting a DNO upgrade. The four-day install only works because the four-week design did.
Who it's for
Commercial fleet operators, transport yards, taxi/private-hire bases, courier depots, service-engineer yards, business parks with shared tenant car parks, hotels with overnight EV demand. Anywhere a single supply has to feed a building and a charging fleet.
Also see: EV chargers, commercial electrical, OZEV grant guide.