68 – Pvd3665_Gb_Ex_August 2022
3.2.11. Rated data according to rated voltage variation
The nominal characteristics and especially the rated speed, maximal speed, rated power,
rated torque, depend on the nominal voltage supplying the motor considered as the rated
voltage. The rated data mentioned in the data sheet are given for each association of motor
and drive. Therefore, if the supply voltage changes, the rated values will also change. As
long as the variation of the rated voltage remains limited, for instance to 10% of the nominal
value, it is possible to correctly evaluate the new rated values as illustrated below.
Example:
Extract of Ex630EAI datasheet
If we suppose that the rated voltage U
n
=400 V
rms
decreases of 10% ; this means that the
new rated voltage becomes U
n2
=360 V
rms
.
Rated speed:
The former rated speed N
n
=3000 rpm obtained with a rated voltage U
n
=400 V
rms
and an
efficiency =92% leads to the new rated speed N
n2
given as follows: