1. Single‑Phase 220V (L–N)

• Household appliances, lighting, small tools, office equipment

• Small shops, temporary construction lighting, low‑power tools

• Total load generally below 10kW

• Simple wiring, easy installation

• Compatible with standard single‑phase equipment

• Low power carrying capacity; high current at the same power

• Severe voltage drop under heavy load

• Not suitable for motors, pumps, compressors, etc.

• Cannot drive three‑phase equipment

2. Three‑Phase 380V (L1–L2–L3)

• Motors, water pumps, fans, air compressors

• Machine tools, production equipment, large heaters

• Farms, construction sites, factories, data rooms

• Total power ≥10kW

• Higher power density, lower line current

• More stable voltage, smaller voltage drop

• Higher efficiency, better for long‑distance transmission

• Required for almost all industrial power equipment

• Requires three‑phase wiring and three‑phase loads

• More complex distribution and protection

3. Key Selection Criteria

By Total Power

• ≤8–10kW: single‑phase 220V is usually sufficient

• ＞10kW: must use three‑phase 380V

  Single‑phase cannot provide enough current and will overheat cables and generators.

By Load Type

• Resistive loads only (lighting, heaters):

  Small power → single‑phase; large power → three‑phase

• Inductive loads (motors, pumps, compressors):

  Must use three‑phase; single‑phase cannot start or operate reliably.

By Wiring and Distance

• Short distance, simple load: single‑phase

• Long cable runs, high power, multiple devices: three‑phase

4. Critical Safety Rule: Phase Imbalance

• Severe phase voltage imbalance

• Generator overheating, vibration, damage to winding

• Unstable operation, protective tripping

• Premature failure of the generator

• Distribute them evenly across L1, L2, L3

• Keep phase imbalance ≤15%

• Never connect large single‑phase loads alone

5. Summary for Generator Selection

• Power <10kW, no motors: choose single‑phase 220V

• Power ≥10kW, or with motors/pumps/compressors: choose three‑phase 380V

• Never mix large three‑phase and large single‑phase loads on the same set

• When using three‑phase, balance single‑phase loads across phases