3.22 Parameters 25-** Cascade Controller
Parameters for conguring 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.
For information on using the advanced features of the cascade controller options, see chapter 3.24 Parameters 27-** Cascade
CTL Option.
To congure the cascade controller to the actual system and the required 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 parameter groups 25-2* Bandwidth Settings and 25-4* Staging Settings often depend on the dynamic of the
system and nal adjustment to be done 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 Conguration Mode). If [0] open loop is selected in parameter 1-00 Conguration Mode, all
xed speed pumps are destaged, but the variable speed pump is still controlled by the frequency converter, now as an
open-loop conguration:
130BA279.12
2 32
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
Illustration 3.79 Cascade Controller Sample Set-up
Parameter Description Programming Guide
MG20OB02 Danfoss A/S © 05/2018 All rights reserved. 207
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