Commissioning – Lenze 8200 Frequency inverters User Manual
Page 118
Commissioning
8200SHB0199
5-13
C014 = -2-
Linear characteristic
C014 = -3-
Square characteristic (e.g. for pumps, fans)
o u t
r m o t o r
V
V
1
V
m i n
0
0
1
C 0 1 5
f
d r m o t o r
o u t
r m o t o r
V
V
V
m i n
0
0
1
C 0 1 5
f
d r m o t o r
K 3 5 . 0 0 6 6 G B
3.Set V
min
boost (C016).
-
Load-independent boost of the motor voltage for field frequencies below the V/f-rated
frequency. It is thus possible to optimise the torque performance of the inverter drive.
-
It is absolutely necessary to adapt C016 to the asynchronous motor used. Otherwise the motor
may be overheated or the inverter may be operated with overcurrent.
Adjustment
Observe the thermal performance of the connected asynchronous motor at low field frequencies
when adjusting it:
-
Usually, self-ventilated standard asynchronous motors with insulation class B can be driven for a
short time with rated frequency with the frequency range between 0 Hz
f
d
25 Hz.
-
Contact the motor manufacturer for exact setting values for the max. permissible motor current in
the lower frequency range of self-ventilated motors.
A Operate the motor in idle running with f
d
slip frequency:
- P
mot
$7.5 kW: f
d
5 Hz
- P
mot
7.5 kW: f
d
2 Hz
Detect the slip frequency:
f
s
f
dr
ô
n
Nsyn
Å n
r
n
Nsyn
n
Nsyn
f
dr
ô 60
p
f
s
Slip frequency [Hz]
f
dr
Rated frequency to motor nameplate [Hz]
n
Nsyn
Synchronous motor speed [min
-1
]
n
r
Rated speed to motor nameplate [min
-1
]
p
No. of pole pairs (1, 2, 3, ...)
B Increase V
min
until the following motor current is reached:
- Motor in short-term operation at 0 Hz
f
d
25 Hz:
Self-ventilated motors:
I
motor
I
r motor
Forced-ventilated motors:
I
motor
I
r motor
- Motor in continuous operation at 0 Hz
f
d
25 Hz:
Self-ventilated motors:
I
motor
0.8 k I
r motor
Forced-ventilated motors:
I
motor
I
r motor
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