Yaskawa VS-626 MC5 - Manual (Page 202)

Advanced Operation
7.4.1 Winding Change Function
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7.4 Optional Functions
7.4.1 Winding Change Function
Winding change motors can be connected in two different ways, Y (low speed) - and (high speed) - wind-
ings.
The base frequency of the Y-winding is lower than that of
-winding, providing higher torque at low
speeds. For the -winding, high speeds are possible.
By switching between the two winding connections, a wide constant power range can be obtained, benefi-
cial for driving the spindle of a lathe or a milling machine.
Power
Y--Winding
0
0 Y--base Y--max
Freq.
winding change
done in this area
--Winding
Freq.
0
0 Y--base Y--max
Power
U V W
X Y Z
6 Lead Motor Winding
U
V W
X--Y--Z
Y--Winding (Y--Connection)
Low Speed, High Torque
U Z
X
V
W
Y
Fig
7.34 Y- and - Windings
Power
high
torque at
low speed
Y--Winding --Winding
0
0
A B
Motor
Speed
Y--base
Speed --max.
Speed
Wind Constant Power Range:
A: B = up to 1: 12
Fig
7.35 Output Performance of Winding Change
7