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Two short courses · ~20 min each

Learn EV installs the
way you'll actually do them.

Bite-size lessons built from the same rules the planner enforces - BS 7671:2018+A4:2026 Section 722, the IET Code of Practice (5th edition), manufacturer enabling works and UK process. Every lesson ends with a quick check; every course ends with a scored knowledge check.

Written by the trade - authored and kept current by a Level 3 qualified installer & commercial PM; 18th Edition (BS 7671), SMSTS, 10+ years of domestic and commercial EV installs.
13
Lessons
13
Quick checks
2
Exams
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Course 01 · Domestic

Home charging, done right

Survey the property, size the load against the main fuse, get PEN protection right, wire and certify the circuit, and hand over a smart, compliant charger.

6 lessons Fuse headroom calculator 8-question check
🏅 Knowledge check passed - best score {{domBest}}/8
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Course 02 · Commercial

Multi-charger sites that pass

Scope supply and demand, design the EVDB and radials, set up dynamic load management, nail civils and comms, and document the job so it signs off first time.

7 lessons DLM sizer 8-question check
🏅 Knowledge check passed - best score {{comBest}}/8
📖 Learn

Short visual lessons - diagrams, key numbers, do/don't lists. No filler.

🎛 Try

Interactive calculators inside the lessons - headroom, DLM sizing, de-rating.

✅ Prove it

Quick checks per lesson, a scored exam per course. Progress saves on this device.
Lesson 1 of 6

Survey the property like it matters

A domestic install lives or dies at the intake position. Before quoting anything, photograph and record four things:

1 · Cut-out (main fuse)

60, 80 or 100 A - the rating cap for the whole house. Never open it; it belongs to the DNO.

2 · Looped supply?

Two houses sharing one service cable. Looped supplies can't use connect-and-notify - refer to the DNO first.

3 · Earthing arrangement

TN-C-S (PME), TN-S or TT - it decides your PEN-fault strategy (lesson 3).

4 · Consumer unit & tails

Spare way? Condition? Tail size? An old board may need a new dedicated enclosure beside it.

Then walk the cable route to the parking spot: measure it, note drilling points and how the car will actually park relative to the charging socket.
Lesson 2 of 6

The main fuse is the budget

A 7 kW charger draws 32 A continuously - on top of showers, ovens and heat pumps. If maximum demand can exceed the cut-out rating, you need a CT load limiter (the charger de-rates when the house is busy - a feature many brands offer, but not all) or a DNO fuse/supply upgrade. Try it:

Main fuse
Household peak
CT load limiter
House {{fuseHouse}} A + charger {{fuseChg}} A = {{fuseTot}} Afuse {{fuseCap}} A
{{fuseVerdict}}

With a limiter, the charger drops as low as ~6 A while the shower runs, then ramps back up - the fuse never sees the sum. That's the same trick commercial dynamic load management uses at scale. Exact floors and behaviour vary by brand and model - check the data sheet before quoting one.
Lesson 3 of 6

PEN faults: the outdoor problem

Most homes are PME (TN-C-S): neutral and earth share one conductor back to the network. If that PEN conductor breaks, the car body outside can rise to mains voltage. BS 7671 gives you three compliant outs:

✓
Built-in open-PEN detection (the usual default)

Most current smart chargers monitor for PEN faults and disconnect all conductors - but it's model-specific, so verify it on the data sheet and record it. Where confirmed, nothing extra to fit.

○
Separate O-PEN device

Only for chargers without built-in detection. Never stack one in front of a charger that already has it - it adds cost and commissioning failures.

⚠
Earth electrode (TT the circuit)

The old way. Brings electrode testing, separation from PME-bonded metalwork and seasonal resistance worries. Last resort.
Lesson 4 of 6

One clean circuit

DNO cut-out
60–100 A
→
Meter + tails
25 mm²
→
40 A RCBO · Type A
30 mA + 6 mA DC
→
Charger
7 kW · 32 A
  • Dedicated radial from the board - nothing else on the circuit, no diversity.
  • Type A RCD + 6 mA DC detection. The DC part is usually inside the charger (RDC-DD); Type AC devices are banned on EV circuits.
  • Cable to suit the run: 6 mm² is a common floor; long garden runs go up a size for volt drop, and anything outside or buried is SWA / EV-grade in duct - never Twin & Earth along the fence.
  • Socket height ~0.75–1.2 m, away from where the car door swings.
Lesson 5 of 6

The paperwork is the product

DNO

Connect & notify within 28 days only if demand stays under the cut-out and ~60 A/phase, supply not looped. Otherwise apply before install via ENA Connect Direct.

Part P

New circuit = notifiable. Self-certify through your competent-person scheme or notify building control.

Smart regs

Chargers sold for home use must be smart: default off-peak schedule, randomised delay, security requirements. Don't defeat them at setup.

EIC

Full certificate with test schedule - Zs, insulation, RCD tests - left with the customer, stating the BS 7671 edition used (A4:2026 from 15 Oct 2026). Plus grant photos if OZEV funding applies.
Lesson 6 of 6

Handover: five minutes that kill callbacks

  • Charge a car (or use the tester) in front of the customer - prove the full start/stop cycle.
  • Set the app up on their phone, not yours: account, Wi-Fi credentials, off-peak schedule matched to their tariff.
  • Show the isolation point and what the status lights mean.
  • Leave the pack: EIC, manufacturer registration/warranty, DNO notification confirmation.
  • Photograph the finished install - position, cable dressing, labels - for your own records and any grant claim.
Tip: most "faulty charger" callbacks are Wi-Fi dropouts or tariff schedules - both are handover failures, not hardware.
Lesson 1 of 7

Scope the site before the sale

Commercial jobs fail in scoping, not installation. Four numbers decide everything:

kVA
Agreed supply capacity
MD
Existing max demand (half-hourly data)
32 A
Per socket, full load, no diversity
m
Route length: trench, duct, containment

Headroom = capacity − MD. If sockets × 32 A doesn't fit, the design conversation is load management or a new connection - decide it now, not at fix stage. Walk the route, photograph the switch room, and count the bays that actually work for charging.
Lesson 2 of 7

Design the electrical spine

Supply
→
Panel board
→
EVDB + SPD
CP-01 · 40 A RCBO · radial 1
CP-02 · 40 A RCBO · radial 2
CP-03 · 40 A RCBO · radial 3
  • A dedicated EVDB near the chargers keeps radials short and future additions cheap - one sub-main upgrade instead of five long runs.
  • Protection per charger type: 40 A DP Type A RCBO (7 kW) · 40 A 4-pole (22 kW) · C40/C63/C80 MCBs for twins with per-socket RCDs inside.
  • Lockable isolation, Type 2 SPD, every way labelled with its charger reference.
Lesson 3 of 7

Load management: more sockets than supply

Dynamic load management (DLM) runs many chargers on one supply: the system de-rates every active unit in real time so the total never exceeds the group limit - typically down to a ~6 A floor, below which chargers queue. Most systems take any mix of 7, 11 and 22 kW AC units from one brand's range. It comes in two flavours: wired (a load management board + screened data cable to every charger) and cloud (balanced over the internet - no board, no data cabling, but every unit needs reliable connectivity). Try the sizer:

Supply
Group limit (per phase)
{{arrSockets}}
max active sockets · ~6 A floor
{{arrEach}}
sockets at ≥16 A each
{{arrBoards}}
boards needed
{{arrNote}}
  • Most systems accept any AC output - 7 kW single-phase, 11 and 22 kW three-phase. Per-charger RCBOs live inside the board on wired groups; cloud groups keep standard protection at the source board.
  • Sub-main sized to the full group limit - no diversity. The limit is set at commissioning and usually stays manually adjustable; many systems let individual chargers be capped too (e.g. one unit held at 16 A).
  • One or two chargers on a tight supply? A CT load limiter does the same job without a group.
Varies by brand & model: DLM is proprietary - floors, mixing rules, offline fallback and remote adjustment differ between manufacturers, and groups are normally single-brand. The sizer shows typical figures; design from the manufacturer's documentation.
Lesson 4 of 7

Earthing across a car park

Same physics as domestic, bigger consequences. TN-C-S and TN-S are straightforward - built-in open-PEN detection covers the PEN-fault risk, no rods, no extra devices. TT is the exception case and carries conditions:

Type B
100–300 mA RCD at source
<200 Ω
electrode resistance
5 m
max rod distance, protected, no tape clamps
2.5 m
clearance from other mains equipment

That last one is the site-layout trap: on TT, a lamp column or barrier on a different earth within 2.5 m of the charger creates a touch-potential hazard. Check it on the plan before civils start, not after.
Lesson 5 of 7

Civils: the ground decides the date

SurfaceCross-section
Concrete base
600 × 600 × 400 · C20
63 mm twin-wall duct, centred, flush
Duct depth · general≥ 450 mm
Under roadway≥ 600 mm
Bend radius≥ 450 mm
Warning tape above duct150 mm
  • Base fully cured before install day - wet concrete is an automatic failed visit and a re-attendance fee.
  • Photograph the bare base before tarmac or paving goes over it; no photo, no warranty on the fixing.
  • Mark bays EV-only (2.4 × 4.8 m) with a contrast strip and wheel stops; plan accessible bays to PAS 1899 while the paint crew is there.
Lesson 6 of 7

No comms, no commissioning

📶 4G - the usual default

Built into many units (not all) - zero setup where fitted, and the usual pick outdoors. Test signal at the charger, phone in hand, before you commit.

📡 Wi-Fi - usually 2.4 GHz only

Most units are 2.4 GHz-only: dedicated SSID, private and secured. No captive portals, no guest networks; mind vendor SSID/password length limits.

🔌 Ethernet - where fitted

Only some models have a port. Shielded Cat5e/6, live before install day, straight onto the network.

Which interfaces a unit offers varies by brand and model - check the data sheet first. A charger that can't connect on install day can't be commissioned - that's a revisit. Confirm the comms method with the client in writing during scoping, and get SSIDs/credentials a week ahead.
Lesson 7 of 7

Programme & paperwork

1
DNO application first

Multi-charger sites are apply-first, via ENA Connect Direct. Since April 2023 you don't pay for upstream reinforcement - but lead times still set your programme.

2
Build the photo record as you go

Photograph everything before it disappears: supply head, protection, cable runs, coiled spares, bare bases. Once surfacing or backfill goes over it, the proof is gone.

3
Install, commission, certify

EIC with schedules for every circuit (including passives), commissioning certificates, asset list with charger serials - stating the BS 7671 edition used (A4:2026 from 15 Oct 2026).

4
Public site? Build in the consumer rules

Chargers the public can use fall under the Public Charge Point Regulations 2023: contactless payment on 8 kW+ units, price in p/kWh displayed, free 24/7 helpline, open OCPI data - and rapids carry the 99% reliability and roaming duties. The terminal and data feed belong in the quote.

£
Claim the grant

Workplace Charging Scheme runs to 31 March 2027 - up to £500 per socket (75% of cost, 40 sockets max) through OZEV-authorised installers, with the installation photos the scheme requires.
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