Wind Turbine Drivetrain Vibration Checker

Per ISO 10816, up to 3.5 mm/s RMS is new-machine condition (zone A) and up to 7.1 mm/s is acceptable for unrestricted long-term operation (zone B). Between 7.1 and 11 mm/s the machine should be scheduled for corrective maintenance (zone C), and above 11 mm/s vibration is severe enough to cause damage (zone D).

Because torque, speed and even alignment change with wind: a gearbox at 30% power can read half its full-power vibration with identical health. Comparing a calm-day reading to a windy-day baseline manufactures false trends. Standard practice (and IEC/VDI guidance) is to trend within fixed power bins — pick one bin and stay in it.

On the gearbox housing (planet/intermediate/high-speed sections) and generator bearings, per the CMS sensor map — as close to the bearing as possible, on stiff metal (never on covers or guards). Take horizontal, vertical and axial readings if you can; use the highest for the ISO grade and always re-measure at the same spot, load and speed.

The usual suspects are gearbox bearing wear (especially high-speed shaft), generator bearing currents, rotor imbalance from blade ice or pitch error, and tower/foundation resonance. A frequency spectrum tells them apart: imbalance shows at 1× running speed, misalignment at 2×, bearing defects at non-synchronous frequencies, and looseness as a raised noise floor with harmonics.

Velocity in mm/s RMS, 10–1,000 Hz. ISO 10816 zone tables are defined on broadband RMS velocity because it weights low- and high-frequency faults evenly for general machines. Acceleration (g) suits high-frequency bearing analysis and displacement (µm) suits low-speed machines, but neither maps onto these zone boundaries.