Siemens SIMOTICS T-1FW68, Configuration Manual

Page: 131 / 194

Technical data and characteristics
6.1 Explanations
1FW68 radial segment motors
Configuration Manual, 08/2021, A5E51132930B AA
129
n
MAX
Maximum speed (maximum permissible operating speed)
n
MAX,MMAX
Maximum speed at which the stator segment can supply the maximum
torque M
MAX
.
n
MAX,INV
Maximum speed at which a Voltage Protection Module VPM is not required.
n
MAX,0
No-load speed; max. speed without load.
M
0
Torque for speed n = 1 r/min at which the load and power loss are still
evenly distributed across all stator segment phases.
I
0
Current (rms value) of the stator segment at torque M
0
and speed
n = 1 r/min.
M
0
* Thermal static torque when the current is unevenly distributed across the
three stator segment phases. An uneven current load occurs in the following
operating modes:
• Standstill
• Operation with short cyclic rotations (< 1 pole pitch)
• For n << 1 r/min
Since the saturation effect can be disregarded for the rated current, the
following applies (approximately):
I
0
* Thermal stall current (rms value) of the stator segment at M
0
* . The following
applies:
Physical constants
D
MOT
Air gap diameter:
n
SEGM
Number of stator segments when fully equipped.
F
A
Force of attraction between a stator segment and the rotor.
k
T,20
Stator segment torque constant at a rotor segment temperature of 20 ° C (refers
to the lower linear range of the torque – current characteristic).
k
E
Voltage constants for calculating the mutually induced line-to-line voltage.
k
M,20
Motor constant for a winding temperature of T = 20 ° C.
The motor constant k
M
(T) can be calculated for other temperatures:
k
M
(T) = k
M,20
∙ [1 + α (T – 20
°
C)]
using the temperature coefficients α = − 0.001 1/K for magnets
k
M
(T) = k
M,20
∙ [1 - 0.001 ∙ (T – 20 ° C)]
t
TH
Thermal time constant of the stator segment winding. This is derived from the
temperature characteristic in the winding with a sudden load and constant
current. See diagram below. After time t
TH
has elapsed, the stator segment
winding reaches approx. 63% of its final temperature T
GRENZ
, if the temperature
protection does not respond beforehand.