Chapter 4 Parameters
VFD-EL-W
4-36
2
nS
2
ttt
xx
p
120
fn
s: operation distance (revolution)
n: rotation speed (revolution/second)
x
t : delay time (second)
2
t : deceleration time (second)
n: rotation speed (revolution/ minute)
p: number of poles in the motor
f: operation frequency (Hz)
The value of
x
t in the equation above describes as below.
When the slope is negative (t1 > t2)
When the slope is positive (t1 < t2)
As shown in the figure below, assume that the radius of the four-pole motor is r and rotation speed is n (RPM).
Example 1
When the motor swivel table rotates at 50 Hz, and Pr.02.02 = 4 [Simple Positioning Stop; E.F.: coast to stop], and
Pr.01.26 = 50 Hz [Simple Positioning Stop Frequency 6], and its corresponding Pr.01.34 = 2 sec. [Delay Time of
Simple Positioning Stop 6], then the deceleration time from 50 Hz to 0 Hz is 10 seconds.
After executing the stop command, Simple Positioning Stop activates, its rotation speed is
n = 120 x 50 / 4 (revolution / minute) = 25 (revolution / second)
The number of revolution of the swivel table = (25 x (2 + 12)) / 2 = 175 (revolutions)