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See also signal flow chart in section 22-2*
No Flow Detection
.
There are three different ways of using the sleep mode function:
1) Systems where the integrated PI controller is used for controlling pressure or temperature, for example, to boost systems with a pressure feedback
signal applied to the adjustable frequency drive from a pressure transducer. par.1-00
must be set for closed-loop and the PI controller
configured for desired reference and feedback signals.
Example: Boost system.
If no flow is detected, the adjustable frequency drive will increase the setpoint for pressure to ensure a slight overpressure in the system (boost to be
set in par.22-45
The feedback from the pressure transducer is monitored and when this pressure has dropped with a set percentage below the normal setpoint for pressure
(Pset), the motor will ramp up again and pressure will be controlled for reaching the set value (Pset).
3 Parameter Description
VLT
®
HVAC Drive Programming Guide
3-202
MG.11.C6.22 - VLT
®
is a registered Danfoss trademark
3