Yaskawa iQpump Controller Programming Manual - Manual (Page 220)

220 YASKAWA TM.iQp.07 iQpump Controller Programming Manual
P7 Anti-Jam / De-Scale
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◆ P7-01 Anti-Jam / De-Scale Operation Selection
NOTICE: Use of the Anti-Jam or De-Scale Functions can force the motor to run in reverse for brief periods. This
can cause pump damage to pumps not designed to run in the reverse direction. To avoid possible pump
damage, do not “Enable” the Anti-Jam or De-Scale Functions.
Setting Range: 0 ~ 3
Factory Default: 0
This parameter provides a method to detect and attempt to expel solids which are keeping the pump impeller from turning. It also
provides rapid bi-directional acceleration at the start to help dislodge scale and buildup attached to the impeller.
Basic Concepts:
Anti-Jam: The drive will monitor output current when starting from zero speed. If the current goes too high, it will coast to a stop then
switch into reverse. The drive will then repeat this cycle until the output current remains below the detection level, or until it faults out on
an “AJF - Anti-Jam Fault”.
De-Scale: The drive will monitor the number of operating hours of the motor. After a set amount of operating time, the drive will go into
the De-Scale function the
next time the drive is started, either in hand or auto mode. This function will run the drive forward, then reverse
for a specified number of times before normal operation will automatically resume.
Anti-Jam and De-Scale are only effective when P1-01 = 0.
■ Function Description:
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Anti-Jam Function: The Anti-Jam function will only operate when all of the following conditions are met:
• P7-01 = 1 Anti-Jam is enabled
• P1-01 = 0 Simplex Operation Only
It will keep monitoring the output current for the time specified by parameter P7-11.
If the drive’s output current goes above the value set in the Anti-Jam Detection Current Level (P7-03), or the drive goes into current limit
for more than the time set in the Anti-Jam Detection Time parameter (P7-04), the “Anti-Jam / De-Scale” alarm will display and the drive
will coast to a stop. After the time set into the Momentary Power Loss Minimum Base Block Time parameter (L2-03) expires, the drive
will attempt to run in reverse at the Anti-Jam / De-Scale Frequency Reference (P7-05). If the current again exceeds the Anti-Jam
Detection Current Level (P7-03) level for more than the time set in Anti-Jam Detection Time (P7-04), the drive will again coast to a stop
and the internal cycle counter will be incremented. This process will then repeat. During this time the integrator of the PI controller will
be held and not allowed to wind-up.
If the internal cycle counter reaches the value set into the Anti-Jam / De-Scale Cycle Count parameter (P7-02), the drive will then fault-
out on an “AJF - Anti-Jam Fault”.
If during the Anti-Jam function the motor current drops below the level set in Anti-Jam Detection Current Level (P7-03) for more than
the time set in Anti-Jam Detection Time parameter (P7-04), the drive will then operate normally. The “Anti-Jam / De-Scale” alarm will
clear, the PI controller will be released and the internal cycle counter will be reset.
De-Scale Function: The De-Scale function will only be allowed to operate when all of the following conditions are met:
• P7-01 = 2 De-Scale is Enabled
• P1-01 = 0 Simplex Operation Only
• b1-02 < 5 “Timed Run” feature is disabled
• P4-14 = 0 Two-Motor Alternation is disabled
• P4-18, P4-29 or P4-20 = 0 Run / Stop control is disabled
While the pump is running (Auto or Hand mode), an internal run timer is activated. This timer is stored in EEPROM at power-down. If
the amount of time accumulated in the timer is less than the De-Scale Pump Run Time parameter (P7-10), the drive starts normally. When
Setting Description
0 Disabled
1 Anti-Jam Enabled
2 De-Scale Enabled
3 Force DeScale