Engineering Information
06.2005
6SE7087-6QX70 (Version AE)
Siemens AG
11-40
Compendium Motion Control
SIMOVERT MASTERDRIVES
M/Nm
n
mean
M
eff
0
2
4
14
500
1000
3000
n/min
-1
1500
2000
2500
6
10
12
8
Fig. 11-21
S1 curve for the 1FT6082-8AF7
The calculated effective motor torque at n
mean
is below the S1 curve.
The motor is therefore suitable.
The inverter is selected according to the maximum motor current and
the mean motor current.
♦
Maximum motor current (the saturation influence here can be
ignored)
I
M
k
A
Mot
Mot
Tn
max
max
.
.
≈
=
=
100
16 57
118
14
♦
Mean motor current, obtained from the magnitude of the torque
characteristic
I
Mot mean
≈
⋅
⋅
∑
M
t
k
T
Mot i
i
Tn
∆
100
=
⋅
+
⋅
+
⋅
+
⋅
+
⋅
+
⋅
⋅
=
16 58 0 6 1147 0 3
6 37 0 6
4 08 0 6
8 39 0 3 12 7 0 6
118 7
3 6
.
.
.
.
.
.
.
.
.
.
.
.
.
. A
♦
A 6SE7021-0TP50 Compact PLUS inverter is necessary with
I
Un
=10.2 A. Since the acceleration and deceleration times are
> 0.25 s, only 1.6 times the rated current can be utilized. Thus
I
A
Mot max
=
14
<
16
16
.
⋅
=
I
A
Un
I
A
Mot mean
=
3 6
.
<
I
A
Un
=
10 2
.
5. Selection of the
inverter
