Yaskawa iQpump Controller Programming Manual - Manual (Page 189)

YASKAWA TM.iQp.07 iQpump Controller Programming Manual 189
Pre-charge with Thrust Bearing Function Both Enabled. <0032>
When both Pre-charge and Thrust Bearing modes are enabled, the system will function as follows: Upon receiving a run command, the
drive will ramp up to the Thrust Bearing Frequency (P4-05) using the Thrust Bearing Acceleration Time (P4-04). After reaching the
Thrust Bearing Frequency (P4-05), the Pre-charge becomes active and P4-05 becomes the new minimum frequency. The drive will ramp
up to the Pre-charge Frequency (P4-02) and will remain at this frequency until the Pre-charge has been completed. This can occur when
the P4-03 time has expired, P4-01 level has been reached, or the Low Water digital input has been deactivated.
If the drive is to stop at any time after the Thrust Bearing Frequency has been reached, the drive will ramp down to the P4-05 frequency
at the rate programmed in Deceleration Time (C1-02). This condition can occur due to loss of run command, auto mode, or drive is in the
sleep mode. The drive will then ramp down from a frequency (P4-05) to 0 using Deceleration Time programmed in P4-06. The Thrust
Bearing Acceleration is active when working from sleep while the Pre-charge is not.
The Pre-charge Frequency (P4-02) should be set to a value greater than the Thrust Bearing Frequency (P4-05). If the Pre-charge
Frequency (P4-02) is less than the Thrust Bearing Frequency (P4-05), the drive will internally use a Pre-charge Frequency equal to the
P4-05 value.
If the Pre-charge Frequency (P4-02) is less than the Minimum Pump Frequency (P1-06), the drive will internally use a Pre-charge
Frequency equal to the Minimum Pump Frequency (P1-06) value.
Figure 1.140
Figure 144.
Run
Command
Output Frequency
Pre-Charge
Frequency P4-02
Thrust Bearing
Frequency P4-05
Pre-Charge
Level P4-01
TIME
Thrust Bearing Mode and Pre-Charge Function in Auto Mode
Standard
Accel Time
C1-01
Thrust Bearing
Accel Time
P4-04
Pre-Charge
Complete
Standard
Decel Time
C1-02
Thrust Bearing
Decel Time
P4-06
Stop due to
Sleep Mode
PI Feedback