Load balance by phase
Even distribution of load across phases L1/L2/L3 — less imbalance, less losses. Automatic balancing and imbalance check per IEC 60364 standard 15–20%.
🔌 Consumers
📊 Phase balance
Why balance the load across phases?
In three-phase networks, uneven load between phases creates current in the neutral conductor, increases losses, and can lead to voltage imbalance. According to IEC 60364, unevenness should not exceed 15–20%.
Unbalance is calculated as the maximum deviation of a phase load from the average value, expressed as a percentage. For example, if L1 — 5 kW, L2 — 3 kW, L3 — 4 kW, average = 4 kW, max deviation = 1 kW, unbalance = 25%.
Proper phase balance reduces the load on the neutral conductor, lowers energy losses, and ensures uniform voltage quality for all consumers.
Typical load distribution across phases in a private house
| Phase | Consumers | Power, kW | Note |
|---|---|---|---|
| L1 | Electric cooktop, oven | 3.5–7.0 | Most powerful consumer — separate phase |
| L2 | Water heater, air conditioner | 2.0–4.5 | Constant base load |
| L3 | Washing machine, sockets | 2.2–3.5 | Variable load |
Approximate distribution for a house of 150–200 m². Exact values depend on the selected appliances — enter your data in the calculator above.
Formula for calculating phase unbalance
D = (Pmax − Pavg) / Pavg × 100%
where: Pmax — load of the most loaded phase (W or kW), Pavg — average load per phase = (L1 + L2 + L3) / 3.
Example: L1 = 5 kW, L2 = 3 kW, L3 = 4 kW. Average = 4 kW. Maximum deviation: L1 deviates by 1 kW.
D = 1 / 4 × 100% = 25% — exceeds IEC 60364 norm 15–20% ⚠️
Load asymmetry (phase imbalance) over 15% causes current in the neutral conductor and voltage imbalance. The calculator above automatically calculates the imbalance and suggests optimal distribution.