Yaskawa iQpump Controller Programming Manual - Manual (Page 22)

22 YASKAWA TM.iQp.07 iQpump Controller Programming Manual
0: Ramp to stop: When the Run command is removed, the iQpump 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 = 0.5 Hz) 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 iQpump drive
shutting off.
Figure 1.14
Figure 14. Deceleration to Stop
The actual deceleration time can be determined by the following formula.
If S-Curve characteristics are specified by the iQpump drive programming, they will add to the total time to stop.
1: Coast to stop: When the Run command is removed, the iQpump 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.
Figure 1.15
Figure 15. Coast to Stop
Important: After a stop is initiated, a subsequent Run commands input before the Minimum Baseblock Time (L2-03) has expired, will
be ignored.
2: DCInj to Stop: When the Run command is removed, the iQpump drive will Baseblock (turn off its output) for the Minimum
Baseblock Time (L2-03). Once the Minimum Baseblock Time has expired, the iQpump drive will inject DC current into the motor
windings to lock the motor shaft. The stopping time will be reduced as compared to Coast to Stop. The level of DC Injection current is set
by parameter b2-02 (50% Default). The DC Injection brake time is determined by the set value in b2-04 and the output frequency at the
time the Run command is removed.
ON
OFF
Run Command
Output Frequency Deceleration Time (C1-02)
DC Injection Brake
100 %
0 %
TIME
| b2-04 |
b2-01
(CLOSED)
(OPEN)
Time to Stop
Output Freq. at time of stop command
Maximum Frequency (E1-04)
------------------------------------------------------------------------------------------- Setting of active Decel Time (C1-02 or C1-04) ×
=
ON
OFF
Run Command
Output Frequency Drive Output Frequency Interrupted
100 %
0 %
TIME
Motor Speed
(CLOSED)
(OPEN)
04) - (E1 Frequency Maximum
Frequency Output 10 04) - (b2
Time Brake Injection DC
× ×
=