Technical information
3.23 Main Menu - Cascade Controller - Group 25
Parameters for configuring the Basic Cascade Controller for sequence control of multiple pumps. For a more application
oriented description and wiring examples, see Chapter Application Examples, item Basic Cascade Controller in the Design
Guide, MG20NXYY.
To configure the Cascade Controller to the actual system and the desired control strategy, it is recommended to follow the
below sequence, starting with parameter group 25-0* System Settings and next parameter group 25-5* Alternation Settings.
These parameter can normally be set in advance.
Parameters in 25-2* Bandwidth Settings and 25-4* Staging settings, will often be dependent on the dynamic of the system
and final adjustment to be done at the commissioning of the plant.
NOTE
The Cascade Controller is supposed to operate in closed loop controlled by the built-in PI controller (Closed Loop selected
in 1-00 Configuration Mode). If Open Loop is selected in 1-00 Configuration Mode, all fixed speed pumps will be destaged, but
the variable speed pump will still be controlled by the frequency converter, now as an open loop configuration:
130BA279.12
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O
At
staging
At
command
At staging
or
command
External
Alt. timer
interval
P 25-52
Sleep
mode
Predened
timer
P 25-54
Disabled Enabled
Slow Quick
No Yes
Disabled Enabled
Direct on line
EnabledDisabledCascade 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):
Cong. of cascade controller
Soft Starter
Conguration mode (P 1-00):
Open Loop
Closed Loop
Parameter Description
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®
HVAC Drive Programming Guide
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