Parker NK Series, Technical Manual, Page: 37 / 100

37 - PVD 3664_GB_NK-November 2016.Docx
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

10% of the nominal value, it is possible to correctly evaluate the new
rated values as illustrated below.
Example:
Extract of NK620EAR 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
=3900 rpm obtained with a rated voltage U
n
=400 V
rms
and
an efficiency of

=92% leads to the new rated speed N
n2
given as follows:


 

1
*
2
2
n
n
n n
U
U
N N
rpm N
n
3476
92 . 0
92 . 0 1
400
360
* 3900
2

 
