Lenze E82xVxxxKxxxxx - Manual (Page 260)

Function library
Operating mode
V/f characteristic control
10
l
260 EDS82EV903 EN 3.0
Set V
min
boost
Load−independent boost of the motor voltage for output frequencies below the V/f rated
frequency. This serves to optimise the torque behaviour.
C0016 must be adapted to the asynchronous motor used. Otherwise the motor may be
destroyed by overtemperature or the controller may be operated with overcurrent:
1. Operate the motor approx. at slip frequency (f
» 5 Hz) when idling:
f
s
+ f
r
@
n
rsyn
* n
r
n
rsyn
n
rsyn
+
f
r
@ 60
p
f
s
Slip frequency [Hz]
fr Rated motor frequency according to nameplate data [Hz]
nrsyn Synchronous motor speed [rpm]
nr Rated motor speed according to nameplate data [rpm]
p Number of pole pairs
2. Increase V
min
until you reach the following motor current:
A Motor during short−time operation at 0 Hz
£ f £ 25 Hz:
– For self−ventilated motors: I
motor
£»
I
rated motor
– For forced ventilated motors: I
motor
£»
I
rated motor
B Motor during continuous operation at 0 Hz
£ f £ 25 Hz:
– For self−ventilated motors: I
motor
£» 0.8
I
rated motor
– For forced ventilated motors: I
motor
» I
rated motor
)
Note!
Observe for all adjusting processes the thermal behaviour of the connected
asynchronous motor at low output frequencies:
ƒ Usually, standard asynchronous motors with insulation class B can be
operated for a short time with their rated current in the frequency range up
to 0 Hz
£ f £ 25 Hz.
ƒ Contact the motor manufacturer for getting the exact setting values for the
max. permissible motor current of self−ventilated motors in the lower speed
range.
C0015
C0016
C0015
2
C0016
2
V [V]
out
f [Hz]
V
(100 %)
rmot
1/N/PE AC 264 V
3/PE AC 264 V
3/PE AC 550 V
1/N/PE AC 180 V
3/PE AC 100 V
3/PE AC 320 V
C0015
C0016
V [V]
out
f [Hz]
V
(100 %)
rmot
1/N/PE AC 264 V
3/PE AC 264 V
3/PE AC 550 V
1/N/PE AC 180 V
3/PE AC 100 V
3/PE AC 320 V
8200vec537 8200vec538
Fig. 10−3 Umin boost at linear and square−law V/f characteristic