Power

The rate of energy transfer or work performed per unit time, the fundamental parameter for selecting power transmission components. Units: kilowatt (kW, SI standard), horsepower (HP, used in the Americas — 1 HP = 0.746 kW, 1 kW = 1.341 HP), and metric horsepower (PS, used in some European catalogs — 1 PS = 0.736 kW). Relationships: P = T × ω = T × 2π × n/60 (where T is torque in Nm and n is RPM), P = F × v (where F is force in N and v is velocity in m/s). In belt drive design: the nameplate motor power is multiplied by the service factor to obtain design power, which determines the belt profile, number of belts, and pulley sizes. Typical motor sizes in Mexico: fractional HP to 500+ HP (follow NEMA MG-1 frame sizes). For conveyor design: P = (belt friction + material lift + acceleration) / drive efficiency. Per IEC 60034 (international motor standards), NEMA MG-1 (North American motors). Conversion factors critical for Mexican/LATAM engineers: HP to kW (×0.746), kW to HP (×1.341), motor RPM at 60 Hz (3,600/1,800/1,200/900 synchronous), torque from power (T(Nm) = 9,549 × P(kW) / n(RPM)).