What Cable, Breaker and Isolator Do You Need for a 7kW EV Charger?
Last updated June 2026. Written for licensed electricians and homeowners planning an EV charger install. Electrical work in Australia must be carried out by a licensed electrician — this guide explains what's involved and the parts you'll need, not a DIY method.
How much current does an EV charger draw?
Charger power is just volts × amps. On a 230 V single-phase supply, a 7.0–7.4 kW charger pulls about 32 A continuously. Because EV charging is a long, sustained load (hours at a time), the circuit is sized for continuous duty with comfortable headroom rather than the bare minimum.
How fast will it charge?
As a rough guide (actual figures depend on the car's onboard charger):
| Charger | Current | Approx. range added/hour |
|---|---|---|
| 2.3 kW (10 A plug-in) | ~10 A | ~10–15 km |
| 7.0–7.4 kW (1φ) | ~32 A | ~40 km |
| 11 kW (3φ) | ~16 A/phase | ~60 km |
| 22 kW (3φ) | ~32 A/phase | ~120 km |
For most households a 7 kW single-phase charger adds a full day's typical driving in a couple of hours and easily tops up overnight — which is why it's the most common home install.
What size cable do I need for an EV charger?
For a typical 32 A single-phase charger on a short-to-medium run, 6 mm² TPS is the usual pick. Long runs, bunched cables or hot roof spaces can push you to 10 mm² to keep voltage drop and derating in check. The table below is a starting point only — the final size comes from an AS/NZS 3008 calculation for your run length and install method.
| Charger | Approx. current | Typical cable* | Typical protection |
|---|---|---|---|
| 3.6 kW (1φ) | ~16 A | 2.5 mm² | 20 A Type A RCBO |
| 7.0–7.4 kW (1φ) | ~32 A | 6 mm² (10 mm² long runs) | 32–40 A Type A RCBO |
| 11 kW (3φ) | ~16 A/phase | 4–6 mm² (5-core) | 20 A 3-pole Type A |
| 22 kW (3φ) | ~32 A/phase | 6–10 mm² (5-core) | 32–40 A 3-pole Type A |
*Indicative only. Actual size depends on run length, install method, grouping and ambient temperature per AS/NZS 3008. For the full method see our cable sizing chart for Australia.
6.0 mm² TPS Twin & Earth — 10 m Cut
The usual choice for a 32 A single-phase EV circuit. Buy by the cut, or save on a 100 m drum.
$90.70 View product →What breaker / RCBO does an EV charger need?
EV circuits need both overcurrent protection and the right kind of RCD (earth-leakage) protection, sized to the circuit — commonly a 32 A or 40 A RCBO for a 7 kW charger. The catch is the type of RCD: EV chargers can produce smooth DC fault currents that "blind" ordinary RCDs, so AS/NZS 3000 requires protection against those DC faults.
| RCD type | Detects | EV suitable? |
|---|---|---|
| Type AC | AC faults only | No — not for EV |
| Type A | AC + pulsating DC | Yes — with 6 mA DC detection (RDC-DD), usually built into the charger |
| Type B | AC + pulsating + smooth DC | Yes — standalone (used where the charger has no DC detection) |
In practice: most home wallboxes have 6 mA DC detection (RDC-DD) built in, so a 30 mA Type A RCBO upstream is enough. Where the charger doesn't, a Type B RCD is used instead. Your electrician confirms which from the charger's manual and the current Wiring Rules. New to the differences? See our explainer on RCD vs RCBO vs MCB and choosing a circuit breaker.
Do I need an isolator for an EV charger?
Yes — a means of isolation lets the charger be safely switched off for maintenance or in an emergency. For an outdoor or carport install this should be a weatherproof (IP-rated) isolator mounted in an accessible spot near the unit. A 2-pole 32 A isolator suits a typical single-phase 7 kW charger. (Not sure what IP rating you need outdoors? See our IP ratings guide.)
Weatherproof Isolator Switch — 2 Pole 32 A
IP-rated isolation for outdoor and carport EV installs.
$9.50 View product →The complete EV circuit — parts checklist
| Component | Typical for 7 kW single-phase |
|---|---|
| Dedicated circuit | Its own way at the switchboard — not shared |
| Cable | 6 mm² TPS (10 mm² for long runs) |
| Protection | 32–40 A Type A RCBO + 6 mA DC detection (or Type B) |
| Isolation | Weatherproof 2-pole isolator near the unit |
| Switchboard | Spare capacity confirmed; load management if needed |
| Charger (EVSE) | Mode 3 wallbox (supplied separately) |
Charging modes: Mode 2 vs Mode 3
- Mode 2 — a portable lead with an in-line control box that plugs into a standard 10 A or 15 A socket. Convenient and slow (around 2.3 kW); fine for occasional top-ups, not ideal for daily charging.
- Mode 3 — a dedicated, hard-wired (or socketed) wallbox that communicates with the car. This is the standard home and workplace install, and what the 7 kW circuit above is built for.
- Mode 4 — DC fast charging found at public stations; not a home install.
Single-phase or three-phase?
Most Australian homes are single-phase, and a 7 kW single-phase charger covers typical daily driving with overnight charging to spare. If the property already has three-phase, an 11 kW or 22 kW charger is an option, but it needs a 5-core cable, a 3-pole RCBO and spare switchboard capacity. Your electrician checks the main switch and supply before recommending three-phase.
Will my switchboard handle it? (load management)
A 7 kW charger adds a continuous 32 A load on top of the existing house demand. On older boards or properties with a limited supply, that can be too much during peak times. Two common fixes: a switchboard upgrade to create capacity, or a load-management (dynamic load balancing) setup that automatically throttles the charger when the rest of the house is drawing heavily. Your electrician will assess the main switch rating, available ways and supply capacity as part of the quote.
The install rules in short (AS/NZS 3000)
- Dedicated circuit — the charger gets its own circuit back to the board; it can't share with power points or lights.
- Correct RCD protection — Type A plus 6 mA DC detection (or Type B), as above.
- Cable sized to AS/NZS 3008 — for current capacity, voltage drop and short-circuit performance.
- Accessible isolation — weatherproof where exposed.
- Licensed electrician only — EV supply equipment must be installed and tested by a licensed electrician; many networks also require notification.
Glossary
- EVSE — Electric Vehicle Supply Equipment (the "charger" / wallbox).
- RCBO — a combined RCD and circuit breaker in one device.
- RDC-DD — residual direct-current detecting device; the 6 mA DC detection often built into chargers.
- Type A / Type B RCD — RCDs rated for different fault-current waveforms (see the table above).
- Mode 3 — dedicated AC charging via a communicating wallbox; the standard home install.
What you'll need from ARCK
We stock the wiring side of the job at trade prices: TPS twin & earth cable, building wire and flex, RCBOs and weatherproof isolators. Browse the full cable range or call the trade counter for a hand picking the right parts.
Frequently asked questions
Can I install my own EV charger in Australia?
No. Hard-wired EV charging equipment must be installed by a licensed electrician. You can plan and buy the parts, but the connection, testing and certification have to be done by a licensed professional.
Is 6 mm² cable enough for a 7 kW charger?
For most 32 A single-phase installs on a short-to-medium run, yes — 6 mm² copper is the common choice. Long runs, bundled cables or hot roof spaces can require 10 mm² to control voltage drop. The exact size is an AS/NZS 3008 calculation.
Do I need a special breaker for an EV charger?
Yes — a Type A RCBO (not Type AC), sized to the circuit, with 6 mA DC fault detection either built into the charger or provided by a Type B RCD. This protects against the DC fault currents EV charging can produce.
How long does it take to charge on a 7 kW charger?
A 7 kW charger adds roughly 40 km of range per hour, so a typical daily commute tops up in a couple of hours and most EVs charge fully overnight. Exact speed depends on the car's onboard charger.
Do I need three-phase for an EV charger?
No. A 7 kW single-phase charger suits most homes. Three-phase (11 kW or 22 kW) only helps if your property already has a three-phase supply and you need faster charging — and it requires a heavier cable and 3-pole protection.
Can I run an EV charger on a normal power point?
A 10 A plug-in lead (about 2.3 kW) can trickle-charge, but it's slow and the socket isn't designed for hours of continuous load. A dedicated 7 kW circuit is far faster and safer for daily charging.
Need a hand picking the parts? Call the trade counter on (02) 9890 9693 or drop in to 589 Church St, North Parramatta. Order online for free Click & Collect, with metro delivery from $19.90 calculated at checkout.