Lenze IE3 g500-B, Project Planning Manual

Page: 24 / 120

General information
Operation with mains power
If operated with mains power, the three-phase AC motor starts up in accordance with the
speed-torque characteristic when switched on. It follows this characteristic until it reaches its
stable operating point. The operating point is reached when the load or rated torque (M
N
) is
smaller than the starting (M
A
) and pull-up torque (M
S
) . The rated speed (n
N
) of the drive is
always less than the arithmetic synchronous speed (n
S
).
The difference between the rated and synchronous speed relative to the synchronous speed is
called the slip.
0.5
1.0
1.5
2.0
2.5
M
A
M
S
M
K
M
N
I
A
I
N
0.2 0.4 0.6 0.8 n
N
n
S
n
K
0
0
M/M
N
n/n
N
1
0
2
3
4
5
I/I
N
Operation on the frequency inverter
Standard setting
The frequency inverter is set for easy operation on a three-phase AC motor with vector
control by default. The rated torque of the motor is available in a setting range up to 50 Hz in
this mode of operation.
Extended setting range up to 87 Hz
If the frequency inverter’s U/f reference point is set to 87 Hz, the rated torque can be taken
into account in an extended setting range. A 230/400 V motor is used here, for example, and
operated in delta on a 400 V frequency inverter. The setting range is increased by 40 %. The
inverter must be dimensioned for a rated motor current of 230 V.
87 Hz f
M, U
M
N
U
AC
U
D,M
50 Hz
Information on project planning
General information
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