Siemens SIMODRIVE 611A, Installation And Planning Manual

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AL S
08.95
AL S/1-3
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Siemens AG 1997 All Rights reserved 6SN1197–0AA20
SIMODRIVE 611 (PJ)
!
Warning
Under fault conditions, the motor can accelerate to n
max
(according to the tech-
nical data), and, for higher supply– or DC link voltages, this speed can be sig-
nificantly exceeded. Only the dynamic torque, limited by the voltage limiting
curve, can occur.
Corresponds in the diagrams to the S1 (100 K) characteristic. The arithmetic
average may not be exceeded, even in intermittent operation.
t
Load duty cycle 10 min
S3–25 %
The power–on duration is, acc. to VDE 0530, normalized for 15 %, 25 %, 40 %, 60 %.
If no duty cycle is specified, it is 10 min.
25 %
Fig. 1-3 Power–on duration in intermittent duty
The motor EMF increases proportionally with increasing speed. Only the differ-
ence between the DC link voltage and the increasing motor EMF is available to
impress the current.This limits the magnitude of the current which can be im-
pressed at high speeds.
!
Warning
It is not permissible for the motor to be continuously operated at the voltage
limiting characteristic in the range above the S1 characteristic for thermal rea-
sons.
The voltage limiting characteristic of a motor with rated speed 6000 RPM lies far
above that of the same motor type with 2000 RPM. However, this motor re-
quires a significantly higher current for the same torque. Thus, it is practical to
select the rated speed, so this does not lie too far above the required maximum
speed for the particular application. This allows the rating of the drive converter
module (current rating) to be minimized.
The voltage limiting characteristics are valid for
1FT5/1FT6
for 600 V and for
1FK6 for 540 V.
Thermal limiting
characteristic
Voltage limiting
characteristic
General information on AC servomotors
1.1 Definitions