Lähtöteho

Lähtöteho, literally “starting power,” is a term used in engineering to describe the power an engine or machine is capable of delivering as it begins to move or start operating from rest. Because power equals torque multiplied by angular velocity, the instantaneous mechanical power at zero speed is zero; therefore lähtöteho typically refers to a transient peak power or the maximum short‑term power available during the initial acceleration under specified conditions, rather than the steady‑state rated power.

Common contexts for the concept include electric motors, generators, and internal combustion engines. In motors, the more relevant consideration is often starting torque and the inrush or starting current; the published starting power is usually a short‑duration figure (milliseconds to seconds) that depends on supply voltage, temperature, and load. This transient power is generally lower than the peak power reached once the machine attains operating speed. Soft‑start controls or variable‑frequency drives can mitigate startup issues by managing this transient.

Lähtöteho is not a long‑term, sustainable rating. It reflects transient capability under conditions at the moment of initiation and is influenced by electrical or mechanical limits, cooling, and voltage stability. The term appears on datasheets to convey how a device performs at start, distinct from its continuous operating power. In practice, it is closely related to, but distinct from, starting torque and transient current.