Parker EX Series, Техническое руководство

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47
– Pvd3665_Gb_Ex_August 2022
3.1.6. 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.
3.1.7. Peak current limitations
It is possible to use the EX 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
EX310
tp<0.8 s tp<0.3s EX420
EX430
EX620
tp<1.5s tp<0.6s
EX630
EX820
EX840
EX860
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