As EV charging, air source heat pumps, and induction cooktops have become standard in Swedish homes, the old single-phase connection is increasingly insufficient. Installing three-phase power is today one of the most common measures we perform on villas in the Stockholm region. Here is everything you need to know.
What is the difference between single-phase and three-phase?
| Feature | Single-phase (1-phase) | Three-phase (3-phase) |
|---|---|---|
| Voltage | 230 V | 400 V (phase-to-phase) |
| Max power (16A fuse) | ~3.7 kW | ~11 kW |
| Max power (25A fuse) | ~5.8 kW | ~17.3 kW |
| Max power (32A fuse) | ~7.4 kW | ~22 kW |
| EV Charger (11 kW) | Requires 32A, can hardly run in parallel | Standard installation |
| Induction cooktop (7 kW) | Uses 30A = little left for others | Takes only one phase |
Single-phase is sufficient for a normal household with an electric stove, tumble dryer, and lighting. It is NOT sufficient for a household that will simultaneously charge an EV + heat the house + cook food.
When MUST you upgrade to three-phase?
You need three-phase if you plan to install:
- EV Charger 11 kW or 22 kW — all fast EV chargers require three-phase
- Air source or geothermal heat pump with high power (>5 kW)
- Induction cooktop in a house with an existing 1-phase connection and other heavy equipment
- Solar panel inverter >5 kW (most are 3-phase)
- Home battery (most systems are three-phase)
The Process: Step by Step
Step 1 — The Electrician's Pre-notification
We send a pre-notification (föranmälan) to your electricity grid company (Ellevio, Vattenfall Elnät, E.ON) stating that you want to upgrade from single-phase to three-phase. It is a legal requirement and usually takes 2–6 weeks to get an answer.
Step 2 — The Grid Company's Investigation
The grid company checks if your current service cable (the cable from the street into the house) already contains 3 phases. It does in about 70–80% of cases in Stockholm — you then only pay for the rebuilding of your internal electrical panel.
If the cable lacks three-phase (older areas, summer house areas), the grid owner is responsible for replacing the cable. They may charge a service fee for this work.
Step 3 — Rebuilding the Electrical Panel
The electrician installs:
- A new three-phase electrical panel (or upgrades the existing one)
- A new three-phase meter space
- Cable attachment and marking
Step 4 — Completion Notification and Meter Change
We send a completion notification (färdiganmälan). The grid company replaces the meter with a three-phase meter, and your three-phase power is ready.
Total time: 4–10 weeks from order to commissioning.
What does it cost to install three-phase?
| Scenario | Cost (gross) | With ROT (-30% on labor) |
|---|---|---|
| Panel already has a 3-phase cable — new panel + meter space | 15,000–25,000 SEK | 12,000–21,000 SEK |
| Service cable lacks three-phase — grid owner's cable work added | +10,000–40,000 SEK (grid owner's fee) | No ROT on the grid owner's part |
| Complete new electrical panel + three-phase upgrade + EV charger | 30,000–55,000 SEK | 24,000–45,000 SEK |
The ROT deduction gives a 30% discount on the electrician's labor cost. The grid owner's service fee is not eligible for ROT.
The smart combination: If you are upgrading to three-phase anyway — take the opportunity to replace the entire electrical panel with a modern one featuring automatic circuit breakers and install the EV charger at the same time. You save a visit and share travel costs.
Frequently Asked Questions about Three-Phase
Can I charge the EV with single-phase? Yes, but a maximum of 7.4 kW (32A single-phase). That provides approx. 35–40 km per hour. With three-phase, you charge at 11 kW (approx. 65 km/h) or 22 kW (approx. 130 km/h). For most people, 11 kW three-phase is sufficient.
Does operating electricity cost more with three-phase? No. You pay for the energy you consume (kWh) regardless of whether you have single- or three-phase. The grid fee may be adjusted for the fuse size, but for the same power output, the cost is identical.
Can I have three-phase in my apartment? Yes, if the building has three-phase to the electrical panel. Contact your tenant-owner association (BRF) or landlord — it is more common in newer buildings.
Need help with this?
Get a free quote from our certified electricians. We usually respond within 24 hours.
Free QuoteDo you want to upgrade to three-phase?
We handle the entire process — from pre-notification to the grid company to a completed certified installation. Contact us for a fixed price proposal tailored to your property.
