Danfoss Metasys N2 Programming Guide

stops energising the motor. When in sleep mode, certain
conditions are monitored to nd out when load has been
applied to the system again.
Sleep mode can be activated either from the no-ow
detection/minimum speed detection (must be
programmed via parameters for no-ow detection, see the
signal ow-diagram in parameter group 22-2*, No-Flow
Detection) or via an external signal applied to 1 of the
digital inputs (must be programmed via the parameters for
conguration of the digital inputs, parameter group 5-1*
selecting [66] Sleep Mode). Sleep mode is activated only
when no wake-up conditions are present.
To make it possible to use for example an electro-
mechanical ow switch to detect a no-ow condition and
activate Sleep mode, the action takes place at the raising
edge of the external signal applied (otherwise the
frequency converter would stay in sleep mode as the
signal would be steadily connected).
NOTICE
If sleep mode is to be based on no-ow detection/
minimum speed, select [1] Sleep Mode in
parameter 22-23 No-Flow Function.
If parameter 25-26 Destage At No-Flow is set for [1] Enabled,
activating sleep mode sends a command to the cascade
controller (if enabled) to start de-staging of lag pumps
(xed speed) before stopping the lead pump (variable
speed).
When entering sleep mode, the lower status line in the
LCP shows Sleep Mode.
See also signal
ow chart in chapter 3.20.1 22-2* No-Flow
Detection.
There are 3 dierent ways of using the sleep mode
function:
130BA255.11
P
f
o
p
SL
FC
S
Illustration 3.51 Sleep mode function
1) Systems where the integrated PI controller is used for
controlling pressure or temperature for example boost
systems with a pressure feedback signal applied to the
frequency converter from a pressure transducer. Set
parameter 1-00
Conguration Mode for [3] Closed Loop and
congure the PI controller congured for desired reference
and feedback signals.
Example: Boost system.
p (Pressure)
Time
Time
No/Low Flow
detected
P 22-45
P 22-44
Sleep mode
activated
Boost
activated
P
Boost
P
Set
P
Wake
f
Ref
f
out
(Frequency)
P
System
130BA257.10
t
1
p
System
= p
Wake
Illustration 3.52 Boost system
If no-ow is detected, the frequency converter increases
the setpoint for pressure to ensure a slight overpressure in
Parameter Descriptions
Programming Guide
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Danfoss Metasys N2 Specifications

General

Brand	Danfoss
Model	Metasys N2
Category	DC Drives
Language	English