Flow Compensation - Danfoss VLT Aqua Drive FC 202 Programming Manual

Programming Guide | VLT® Aqua Drive FC 202
Setup: All setups
Data type: Int32
Set the feedback value at which the minimum-run-time timer must be overridden. When the feedback drops below this value, the motor
is destaged even if the minimum-run-time timer has not expired.
5.21.7

22-8* Flow Compensation

Sometimes it is not possible for a pressure transducer to be placed at a remote point in the system, and it can only be placed close
to the fan/pump outlet. Flow compensation operates by adjusting the setpoint according to the output frequency, which is almost
proportional to flow, thus compensating for higher losses at higher flow rates.
H (required pressure) is the setpoint for closed-loop (PI) operation of the drive and is set for closed-loop operation without flow
DESIGN
compensation.
It is recommended to use slip compensation and RPM unit.
Figure 101: Flow Compensation
When flow compensation is used with the cascade controller (parameter group 25-** Cascade Controller), the actual setpoint does
not depend on speed (flow), but on the number of pumps cut in.
H (head)
H DESIGN
Setpoint
H MIN
P22-87
1
Figure 102: Flow Compensation with Cascade Controller
There are 2 methods which can be employed, depending on whether or not the speed at system design working point is known.
© 2024.06
2 3
Number of pumps
Conversion index:
Change during operation:
NOTICE
Parameter Descriptions
-3
True
AU361182657213en-002101 / 130R0338 | 503