If solenoids are to operate reliably, they must be provided with suitable power; the following are a few terms to aid in understanding:

9.1 Nominal voltage
The nominal voltage is that with which a solenoid is normally operated, the tolerance is +5% to -9%.

9.2. Nominal current
The nominal current given in the data sheets is always referenced to the rated voltage and a winding temperature of 20 °C.

9.3. Nominal power
The nominal power (in W) is calculated from the rated voltage and current (at a winding temperature of 20 °C) given in the data sheets.

9.4. Test voltage
Solenoids are tested for electrical insulation and dielectric strength at a certain test voltage that lies above the rated voltage. The test voltage is applied between the exciter winding and the metal parts of the unit that can be touched.