Instruction manual

Cascade Controller Option
Quick Menu 029 Par. 418 Setpoint 1
(SETPOINT 1)
Value:
Feedback Min. to Feedback Max
✭ 0.000
Function:
The default feedback process is used when a pressure
feedback signal is measured at the outlet of the
pumps. The cascade controller uses the feedback
to estimate the setpoint required at various rates of
flow. All other reference signals are ignored. Setpoint
1 is the minimum pressure required when the system
is running with only the AFD operating at full speed.
Setpoint 1 is a theoretical value that the cascade
controller uses as an internal reference to calculate
pressure loss in the system under minimum load.
The controller adjusts the internal reference based
upon the number of pumps in operation.
The range is determined by Quick Menu item 14
(parameter 413, Minimum Feedback)andQuickMenu
item 015 (parameter 414, Maximum Feedback).
When the pressure feedback signal originates at
the far end of the system, the drive does not need
to compensate for system pressure changes due
to flow. For this system configuration, or for two
setpoint PID control, see Alternative Programming
at the end of this chapter.
Description of choice:
Set the desired feedback minimum within the
programmed minimum and maximum in Quick Menu
items 014 and 015. The process uni
t is selected
in Quick menu item 013, Process Units.
NOTE
Factory setting is for a single 4 - 20 mA current
signal transmitter for process feedback. In
all other cases, see instructions in Chapter
10, Feedback Transmitter Wiring.
Quick Menu 030 Par. 419 Setpoint 2
(SETPOINT 2)
Value:
Feedback Min. to Feedback Max.
✭ 0.000
Function:
The default feedback process is used when a pressure
feedback signal is measured at the outlet of the pumps.
The cascade controller uses the feedback to estimate
the setpoint required at various rates of flow.
All other reference signals are ignored. Setpoint 2 is
the maximum pressure required when the system is
running with all pumps at full capacity. A theoretical
value calculates pressure loss in the system under
maximum load. The controller adjusts the loading
based upon the number of pumps in operation.
The range is determined by Quick Menu item 014
(parameter 413, Minimum Feedback) and Quick Menu
item 05 (parameter 414, Maximum Feedback).
When the pressure feedback signal originates
at the far end of the system, the drive does not
need to compensate for system pressure changes
due to flow. For this system configuration, or for
two setpoint PID control, or for water pumping
systems where the feedback signal is measured
across the outlet of the pumps, see Alternative
Programming at the end of this chapter.
MG.60.I5.22 - VLT is a registered Danfoss trademark
45
Standard Cascade
Controller Setup