BENSHAW RSi H2 Series - Pre-PID and Soft Fill Operation

PID Control
235
890053-00-02
6.3.3 Pre-PID and Soft Fill Operation
Pre-PID and Soft Fill are two separate operations. Both are used to prevent excessive pressure
from building in the pipe system during the initial stages of pump operation.
Pre-PID - At start, Pre-PID (without PID control) begins and continues at the Pre-PID frequency
(AP1-21) for the time set at AP1-22. The Pre-PID operation continues until either the feedback
value reaches the Soft Fill Set (escape value, AP1-23) or the time (AP1-22) expires. If the system
has built up enough pressure (or other units) to meet the AP1-23 escape value, Normal PI Control
will begin. If the system has not built-up pressure (or other units) to meet the AP1-23 escape
value, Soft Fill operation begins.
Soft Fill operation automatically changes the PI Reference (setpoint) set in PID-10 and PID-11 to
a "Soft Fill" PI Reference (setpoint). The Soft Fill PI Reference performs a series of steps that
increase over time to slowly fill a piping system. The steps are defined by parameters AP1-24 (Fill
Step Set) and AP1-25 Fill Step Time) as defined below. When the system has built up enough
pressure (or other units) to meet the AP1-23 escape value, Normal PI Control will start.
Group
Code
Name
LCD Display
Parameter Setting
Setting Range
Unit
AP1
20
Soft Fill options
Soft Fill Sel
0
No
0–1
-
21
Pre PID operation
frequency
Pre-PID Freq
30.00
Low Freq– High
Freq
Hz
22
Pre-PID duration
Pre-PID
Delay
60.0
600.0
sec
23
Soft fill escape value
Soft Fill Set
20.00
Unit Min–Unit
Max
%
24
Soft fill reference
increment
Fill Step Set
2.00
0–Unit Band
%
25
Soft fill reference
increment cycle
Fill Step Time
20
0–9999
sec
26
Soft fill feedback
difference
Fill Fdb Diff
0.00
0–Unit Band
%
Soft Fill Operation Setting Details
Code
Description
AP1-20
Soft Fill Sel
Set to ‘Yes’ to enable both Pre-PID and Soft Fill operation.
Set to ‘No’ to disable Pre-PID and Soft Fill operation.
AP1-21
Pre-PID Freq
Set the inverter output frequency during Pre-PID. The Pre-PID operation
continues until either the feedback value reaches the Soft Fill Set (escape
value, AP1-23) or the time (AP1-22) expires.
AP1-22
Pre-PID Delay
Set the Pre-PID time. The Pre-PID operation continues for this time period
until either the feedback value reaches the Soft Fill Set (escape value, AP1-
23) or this time expires.
AP1-23
Soft Fill Set
Set the feedback amount. When feedback reaches this amount at any time
during Pre-PID or Soft Fill, the inverter exits the operation and normal PI
Control begins.