Lenze IE3 g500-B, Project Planning Manual

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Torque reduction at low motor frequencies
At low motor frequencies (usually < 20 Hz) and with an integral fan, the motor is not cooled
sufficiently at the rated torque. The motor can be operated from 5 Hz by reducing the torque
accordingly.
Constant cooling takes place over the entire speed range in motors with a blower. This means
that they can be used with their rated torque from 5 Hz.
The diagram shows the motor size-dependent torque reduction for self-ventilated motors,
taking into account the thermal behavior during operation at the inverter.
50 Hz
60 Hz
87 Hz
1.0
0.9
0.8
0.7
0.6
0.5
0.4
M/M
N
0
5
10 20 30 40 50
60
70 80 90 100
14 87
f [Hz]
B
A
C
D
m540-P
A Operation with integral fan and brake
B Operation with integral fan and brakes with a wide range voltage of DC 180 ... 205 V or AC 400 ... 460 V
Operation with integral fan and "holding current reduction" brake control
C Operation with blower
D Operation below 5 Hz is possible depending on the application and the control method.
Verification of the application by Lenze required.
Thermal power limit
The thermal power limit, defined by the heat balance, limits the permissible continuous
gearbox power. It is affected by
•
the churning losses in the lubricant. These are determined by the mounting position and
the circumferential speed of the gears
•
the load and the speed spectrum.
•
the ambient conditions: temperature, air circulation, input or dissipation of heat via shafts
and the foundations.
Information on project planning
General information
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