YASKAWA E7U Programming Manual page 13

"0:Ramp to stop": When the Run command is removed, the Drive will decelerate the motor to 0 rpm. The rate of
deceleration is determined by the active deceleration time. The factory default Decel Time is in parameter C1-02.
When the output frequency has dropped below the DC Injection Start Frequency in b2-01 (Default = 0.5HZ) DC current will
be injected in the motor at a level determined by b2-02 (50% Default). The DC Injection condition will occur for the time
specified by b2-04 (0.0 Default), to establish the end point of the ramp. DC injection can be used to insure the motor is at zero
rpm prior to the Drive shutting off.
Run Command
Output Frequency
The actual deceleration time can be determined by the following formula
Output Freq.
=
Time to Stop
Maximum
If S-Curve characteristics are specified by the Drive programming, they will add to the total time to stop.
"1:Coast to stop": When the Run command is removed, the Drive will turn off its output and the motor will coast
(uncontrolled deceleration). The friction of the driven equipment will eventually overcome any residual
inertia of the system and the rotation will stop.
Run Command
Output Frequency
After a stop is initiated, a subsequent Run commands input before the Minimum Baseblock Time (L2-03)
IMPORTANT
has expired, will be ignored.
100 %
Deceleration Time (C1-02)
0 %
Fig. 4 Deceleration to Stop
at time of stop command
Frequency (E1 - 04)
100 %
0 %
TIME
×
Setting of active Decel
Motor Speed
Drive Output Frequency Interrupted
TIME
Fig. 5 Coast to Stop
Programming 7
(CLOSED)
ON
(OPEN)
OFF
b2-01
DC Injection Brake
| b2-04 |
02 or C1-04)
Time (C1 - 02)
ON
OFF
(CLOSED)
(OPEN)