Danfoss VLT, Руководство по программированию

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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.
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 commis-
sioning 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
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
Parameter Description
VLT
®
HVAC Drive Programming Guide
168 MG.11.CB.02 - VLT
®
is a registered Danfoss trademark
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