| average relative humidity | The high-voltage switchgear and controlgear average value of the relative humidity measured over a period of 24h in accordance with IEC 62271-1 | Number |
| efficiency | Ratio of an output power to an input power | Number |
| efficiency at 100% rated output | The efficiency of the motor whilst operating at 100% rated power | Number |
| efficiency at 50% rated output | The efficiency of the motor whilst operating at 50% rated power | Number |
| efficiency at 75% rated output | The efficiency of the motor whilst operating at 75% rated power | Number |
| efficiency at lower limit continuous operating speed | The efficiency at maximum continuous operating speed at the maximum torque value of the load window as per IEC 61800-4 | Number |
| efficiency at maximum continuous operating speed at maximum torque | The efficiency at maximum continuous operating speed at the upper torque value of the load window as per IEC 61800-4 | Number |
| efficiency at upper limit continuous operating speed at upper torque value | The efficiency at maximum continuous operating speed at the maximum torque value of the load window as per IEC 61800-4 | Number |
| head weld joint efficiency | Is a joint efficiency factor that is a correction factor for the strength of a weld dependent on the type and percentage examination Its value is 1 in case of 100% radiographic examination | Number |
| locked-rotor power factor at 100% rated voltage | The power factor with the rotor locked, at rated voltage and frequency | Number |
| locked-rotor torque in % of full load torque at 100% of rated voltage | The smallest measured torque the motor develops at its shaft and with the rotor locked, over all its angular positions, at rated voltage and frequency | Number |
| locked-rotor torque in % of full load torque at 80% of rated voltage | The smallest measured torque the motor develops at its shaft and with the rotor locked, over all its angular positions, at 80% rated voltage and rated frequency | Number |
| lower limit site relative humidity | The humidity which is the lowest relative humidity at the site where the physical object is expected to operate | Number |
| lower limit specific heat ratio Cp/Cv | The specific heat ratio which is the lowest specific heat for the process medium | Number |
| normal specific heat ratio Cp/Cv | The specific heat ratio which is the normal specific heat for the process medium | Number |
| power factor at 100% rated output | The cosine of the angle between active power and apparent power when the motor is operated at 100% rated power | Number |
| power factor at 50% rated output | The cosine of the angle between active power and apparent power when the motor is operated at 50% rated power | Number |
| power factor at 75% rated output | The cosine of the angle between active power and apparent power when the motor is operated at 75% rated power | Number |
| power factor at lower limit continuous operating speed | The cosine of the angle between active power and apparent power at the lower limit continuous operating speed at the upper torque value of the load window as per IEC 61800-4 | Number |
| power factor at upper limit continuous operating speed | The cosine of the angle between active power and apparent power at the upper limit continuous operating speed at the upper torque value of the load window as per IEC 61800-4 | Number |
| rated power factor (lagging) | Dimensionless number between 0 and 1 Cos F = P/S Where P = upper limit power consumption and S = apparent Power | Number |
| service factor | The percentage of overloading the motor can handle for short periods when operating normally within the correct voltage tolerances | Number |
| shell weld joint efficiency | Is a joint efficiency factor that is a correction factor for the strength of a weld dependent on the type and percentage examination Its value is 1 in case of 100% radiographic examination | Number |
| short-circuit current in neutral conductor and in protective circuit | The low voltage switchgear and controlgear short-circuit current in neutral conductor and in protective circuit in accordance with IEC 61439-1 | Number |
| specific heat ratio Cp/Cv at inlet | The specific heat ratio for the process medium at inlet conditions | Number |
| subtransient reactance | Quotient of the initial value of a sudden change in that fundamental AC component of primary voltage, which is produced by the total direct-axis primary flux, and the value of the simultaneous change in fundamental AC component of direct-axis primary | Number |
| upper limit relative humidity | The highest relative humidity at which a functional or physical object is designed for | Number |
| upper limit specific heat ratio Cp/Cv | The specific heat ratio which is the highest specific heat for the process medium | Number |
