Model guide
Vestas V126-3.45 MW
Vestas’ 3 MW-class (today’s 4 MW platform) medium-wind model. The first version was 3.3 MW, the common one is 3.45 MW; the rotor is 126 m. Unlike the V110 it uses a full-scale converter, so all the power passes through the converter.
What defines this model
The V126 was designed for medium-wind, high-turbulence sites (IEC IIIA / IIB). Its 12,469 m² swept area catches roughly a third more wind than the V110.
The drivetrain uses a gearbox with two planetary stages and one helical stage. The full-scale converter decouples the generator from the grid: grid events reach the generator less, while converter cooling and power-electronics maintenance move to the centre of the work.
Key technical data
| Parameter | Value |
|---|---|
| Rated power | 3.3 MW (first version) / 3.45 MW |
| Rotor diameter | 126 m |
| Swept area | 12,469 m² |
| Hub height (3.45 MW) | 87 / 117 / 137 / 147 / 149 / 166 m |
| Cut-in | 3 m/s |
| Cut-out | 22.5 m/s |
| Wind class | IEC IIIA / IEC IIB |
| Gearbox | 2 planetary + 1 helical stage |
| Converter | Full scale |
| Pitch | Full-blade feathering, one pitch cylinder per blade |
Drivetrain and systems
Gearbox
- Two planetary stages carry high torque in a compact housing; planet gear and bearing condition are followed through oil analysis and vibration trends.
- Filter differential pressure, oil temperature and cooler cleanliness are read together.
Full-scale converter
- Because all the power passes through the converter, its cooling circuit (fluid level, pump, fan, radiator) and power-connection torque are critical maintenance items.
- A thermal scan under load catches loose connections that never show on a stopped turbine.
Hydraulic pitch
- One pitch cylinder per blade. The accumulators and hydraulic unit hold the energy to feather the blades on grid loss.
V126 and V136 (Vestas)
| Item | V126-3.45 MW | V136-4.2 MW |
|---|---|---|
| Rotor diameter | 126 m | 136 m |
| Swept area | 12,469 m² | 14,527 m² |
| Gearbox | 2 planetary + 1 helical | 2 planetary + 1 helical |
| Converter | Full scale | Full scale |
Maintenance topics that matter in the field
- Converter cooling: a dirty radiator or low fluid level is a common cause of temperature and overcurrent faults at high power.
- Gearbox oil temperature and filter alarms: trend tracking and oil samples.
- Hydraulic leaks and accumulator pre-charge.
- Blade bearings and root bolts: periodic checks and lubrication.
Sources
Warning: Every job in the nacelle, hub and tower follows lockout–tagout (LOTO), rotor lock and the manufacturer’s safety instructions. This page is field experience and published data; it does not replace the service documentation.