12 - PVD 3661 MGV_ commisionning manual_March 2012.docx
Other limitations can come from the bearing type
(steel straight, hybrid or Xlife)
Cf: §3.4 Bearing
3.1.6.
Recommended reduced current at speed < 3 rpm:
Current limitation at stall conditions (i.e. 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 MGV motors 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):
0
0.5
1
1.5
2
2.5
3
3.5
0
5
10
15
20
25
Pea
k
cu
rr
en
t/
Lo
w
sp
eed
cu
rre
nt
Time
I/Io
tp
tc
