P1
P2
P3
P4
The offset voltage limiting characteristic curve is obtained with points P2 and P4.
Example of offset of voltage limiting characteristic curve without field weakening
Motor 1FT7042-5AF71; n
U
mot new
U
iN
Condition U
Enter and connect points P2 and P4. This line is the new voltage limiting characteristic for
U
mot new
1FT7 Synchronous Motors
Configuration Manual, (PFT7S) 01/2009, 6SN1197-0AD13-0BP2
Intersection between voltage limiting characteristic and x axis: Read off or calculate
the speed
The point where the voltage limiting characteristic intersects with the x axis is shifted
from n
to n
.
1
2.
Read-off M
on the voltage limiting characteristic curve specified for V
limit
Calculate M
limit, new
N
= 290 V; calculated with U
= k
∙ n
/1000; U
= 87 ∙ 3000/1000 = 261 V
E
N
iN
> U
is fulfilled.
mot, new
iN
= 290 V.
= 3000 RPM; k
= 87 V/1000 RPM
E
= 380 V (diagram [a])
mot
Technical data and characteristic curves
4.1 Operating range and characteristics
.
mot
77