User's Manual

Technical data and characteristics
14.1 Explanations of the formula abbreviations
n
MAX,MMAX
Maximum speed up to which the motor can deliver the maximum torque M
MAX
.
n
MAX,0
No-load speed; max. speed without load.
M
0
Torque for speed n = 1 [rpm] at which the load and power loss are still evenly
distributed across all three motor lines.
I
0
Current (rms value) of the motor at torque M
0
and speed n = 1 [rpm].
M
0
* Thermal static torque when the current is unevenly distributed across the three
motor lines. An uneven current load occurs in the following operating modes:
 Standstill
 Operation with short cyclic rotations (< 1 pole pitch)
 For n << 1 [rpm]
Since the saturation effect can be disregarded for the rated current, the
following applies (approximately):
I
0
* Thermal stall current (rms value) of the motor at M
0
*
. The following applies:
Physical constants
k
T,20
Motor torque constants at a rotor 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 at a winding temperature of T = 20 °C.
The motor constant k
M
(T) may be calculated for other temperatures:
k
M
(T) = k
M,20
∙ [1 + α(T – 20 °C)]
with temperature coefficient 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 motor winding. This is derived from the temperature
characteristic in the winding with a sudden load and constant current. See
diagram below. When the time t
TH
has elapsed, the motor winding reaches
approximately 63% of its final temperature T
GRENZ
if thermal protection was not
active prior to this.
1FW6 Built-in torque motors
Configuration Manual, 05/2009, 6SN1197-0AE00-0BP3
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