3.23 Parameters: 25-** Cascade Controller
Parameters for configuring the basic cascade controller for sequence control of multiple pumps. For a more application-
oriented description and wiring examples, see
Application Examples, Cascade Controller
in the design guide.
To configure the cascade controller to the actual system and the desired control strategy, follow the sequence, starting with
parameter group
25-0* System Settings
and next parameter group
25-5*
Alternation Settings
. These parameters can normally
be set in advance.
Parameters in
25-2* Bandwidth Settings
and
25-4* Staging Settings
often depend on the dynamic of the system and final
adjustment to be d1 at the commissioning of the plant.
NOTICE
The cascade controller is supposed to operate in closed loop controlled by the built-in PI controller (
[3] closed loop
selected in
parameter 1-00 Configuration Mode
). If
[8] open loop
is selected in
parameter 1-00 Configuration Mode
, all
fixed speed pumps are destaged, but the variable speed pump is still controlled by the frequency converter, now as an
open-loop configuration:
130BA279.12
2
3
2
Off
At
staging
At
command
At staging
or
command
External
Alt. timer
interval
P 25-52
Sleep
mode
Predefined
timer
P 25-54
Disabled
Enabled
Slow
Quick
No
Yes
Disabled
Enabled
Direct on line
Enabled
Disabled
Cascade controller (P 25-00):
Number of pumps (P 25-06):
Motor start (P 25-02):
Pump cycling (P 25-04):
Fixed lead pump (P 25-05):
Lead pump alternation (P 25-50):
Alternation Event (P 25-51):
Alt. if capacity<50% (P 25-55):
Staging mode at alternation (P 25-56):
Config. of cascade controller
Soft Starter
Configuration mode (P 1-00):
Open Loop
Closed Loop
Illustration 3.67 Cascade Controller Sample Set-up
Parameter Descriptions
VLT
®
HVAC Drive FC 102
190
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MG11CE02
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