Can I charge 3-phase on an IT grid?
Yes, but it also depends on your EV and charging cable.
Many EV owners wonder if they can charge on a 3-phase IT (230V) grid. While Zaptec Go supports all power grids (TN, IT, TT) with both 1-phase and 3-phase charging, not all EVs are designed to fully utilize 3-phase charging on IT.
- 3-phase charging on IT can be faster, but only if your EV supports it. If not, your EV will default to 1-phase charging (7.4kW max).
- Tip: Lower charging power can reduce your electricity bill by avoiding peak power tariffs.
The diagram in the article illustrates how different factors (like your car's OBC) impact the final charging power.
Understanding your power grid
Norway has three types of power grids:
- TN (400V) – The most flexible for charging.
- IT (230V) – Common, but some EVs have limitations for 3-phase charging.
- TT (230V) – Similar to IT, but less common.
Not sure which grid you have? Check your fuse box for labels like IT (230V), TN-C (400V), or TN-S (400V). If you don't see it, check your circuit breaker, or ask an electrician.
Why does my power grid matter?
- If you're connected to a 3-phase TN system (400V), you have few charging restrictions.
- On a 3-phase IT or TT system, your EV's onboard charger (OBC) decides how much power it can use (the utilization of the phases).
This only applies to 3-phase setups. If your home only has 1-phase power, charging speed will be the same across all grid types.
How 3-phase charging works on an IT grid
Zaptec Go & IT grid: What to Expect
Zaptec Go supports charging on a 3-phase IT system, but your EV's onboard charger (OBC) determines the actual charging power.
- The maximum possible power on IT 3-phase would be 12.7kW.
- There are currently no cars that fully support charging on IT 3-phase charging.
- Tesla Model 3/Y is the car model that chargers fastest on IT 3-phase today (max 11kW).
- Most other EV's are limited to 7.4kW (1-phase, 32A).
There are some EVs that partially support charging on IT 3-phase. These cars gain only about 1kW extra in charging speed - the same as charging an additional 0.5 miles per hour. However, the majority of EVs will be able to get 7.4kW (1-phase. 32A) in an IT network.
What does this mean for you?
If your EV doesn’t support full 3-phase charging on IT, you’ll get the same speed as a 1-phase setup (7.4kW).
Charging power and safety
Zaptec Go supports both 1- and 3-phase charging, with a maximum output of 22kW, but your actual charging speed depends on four key factors:
- Power grid (IT, TT, TN).
- Installation of the charging station.
- Charging cable (1-phase or 3-phase).
- Car's onboard charger (OBC).
The weakest factor determines your charging speed.
For example:
- If your EV supports IT 3-phase, you may get up to 11kW.
- If your EV doesn't fully support IT 3-phase, you'll get 7,4 (kW) (1-phase).
How to read the table
The table under shows the max power output for different combinations of grid type, installation, cable, and car. The weakest factor in the chain is marked in red, clearly showing what limits charging speed.
Safety first!
Zaptec Go automatically detects how many phases it's connected to and adjusts accordingly.
- If it is connected as 3-phase, it will pass through all three phases.
- If it's connected as 1-phase, it will only use one phase.
- Zaptec Go cannot switch between 3-phase and 1-phase automatically during charging - this is a safety requirement.
Why can't Zaptec Go switch between 3-phase and 1-phase automatically?
This is due to a safety requirement for an all-pole break in the safety relay for the earth fault circuit breaker. This means all three phases are ON or OFF at the same time.
What does this mean for you as a user?
If you have a TN (400V) network, this won't affect you - all EVs charge without issues. However, if you have a 3-phase IT (230V) network, and your EV doesn't fully support it, then:
Zaptec Go will detect that power is only being drawn from one phase and allow charging up to 32A/7.4kW.
The exception: Some 1-phase EVs do not charge at all on IT 3-phase.
In that case, you have two options:
- Ask an electrician to install Zaptec Go as a 1-phase charging station.
- Use a 1-phase charging cable, which acts as a bottleneck for power.
Regardless of choice, you will be able to get a maximum output of 7.4kW.
Best solution if you have two EVs: If one EV supports 3-phase IT charging and the other doesn't, option 2 is best - this way, you can still charge with 3 phases when needed.
Avoiding high power tariffs and saving money
Electricity tariffs are based on how much power you use at the same time. If you're charging your EV while also running appliances like heating, a washing machine, or an oven—you may move into a higher price bracket, increasing your electricity bill.
Even if your EV supports IT 3-phase charging, it may not always be the most cost-effective option.
Power companies charge based on peak power usage rather than total energy consumed. This means your bill is affected by the highest power demand at any one time, rather than just how long you charge.
Example:
If you have an electric car and charge at home, you will quickly
end up at stage 3 (5-5kW) or 4 (10-15kW). The cost still vary from
company to company. At BKK, it costs NOK 350 per month at stage 3
and NOK 494 at stage 4, including VAT. At Lyse, the prices are
NOK 350 and NOK 475 respectively.
Source: BKK, Lyse, House owners in Elbil24.no
How to reduce charging costs
Use 1-phase charging when possible – If 7.4kW is enough for your daily driving, using 1-phase charging instead of 3-phase can help keep your peak power lower.
Charge overnight during off-peak hours – Some electricity providers have cheaper rates at night when overall power demand is lower. Scheduling your EV to start charging after midnight can help save money.
FAQ
How do I check if my car supports 3-phase charging on IT?
Contact the car manufacturer or check your EV's technical specifications.
What happens if I use a 1-phase cable on a 3-phase charger?
The charger will detect the capacity of the charging cable that is connected and limit charging to 1-phase automatically. E.g. If you use a 1-phase cable on a 3-phased wired charger it will behave as if it were connected to a 1-phase.
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