Parker NX Series, Техническое руководство, Страница: 19 / 116

19 - PVD 3663_GB_NX_March 2017.Docx
3.1.5. Current limitation at stall conditions (i.e. speed < 3 rpm)
Recommended reduced current at speed < 3 rpm:
0 0
* 0.7 *
2
1
I I I
reduced
 
Warning: The current must be limited to the prescribed values. If the
nominal torque has to be maintained at stop or low speed (< 3 rpm),
imperatively limit the current to 70% of I
0
(permanent current at low
speed), in order to avoid an excessive overheating of the motor.
Please refer to the drive technical documentation for any further
information and to choose functions to program the drive.
3.1.6. Peak current limitations
It is possible to use the NX motor with a current higher than the permanent current.
But, to avoid any overheating, the following rules must be respected.
1) The peak currents and peak torques given in the data sheet must never be
exceeded
2) The thermal equivalent torque must be respected (§3.1.3)
3) If 1) and 2) are respected (it can limit the peak current value or duration), the
peak current duration (tp) must be limited, in addition, accordingly to the
following table (Io is the permanent current at low speed):
Ipeak/In
Ip/Io =2 Ip/Io = 3 Ip/Io =4 Ip/Io >5
NX110
tp<0.8 s tp<0.3s tp<0.15s tp<0.1s
NX210
NX310
NX420
NX430
NX620
tp<1.5s tp<0.6s tp<0.3s tp<0.2s
NX630
NX820
NX840
NX860
NX860V
tp<3s tp<1.5s not allowed
NX860W
The peak current duration is calculated for a temperature rise of 3°C
Consult us for more demanding applications.
0
1
2
3
4
0 5 10 15 20 25
Peak
c
u
rr
e
n
t/
Low
sp
e
e
d
cu
rr
e
n
t
Time
I/Io
tp
tc