When low power or low speed is detected the motor is stopped, but the reference signal (f
ref
) from the external controller is still monitored and because
of the low pressure created, the controller will increase the reference signal to gain pressure. When the reference signal has reached a set value f
wake
the motor restarts.
The speed is set manually by an external reference signal (Remote Reference). The settings (par. 22-3*) for tuning of the No Flow function must be set
to default.
Configuration possibilities, overview:
Internal PI Controller
(Par. 1-00: Closed loop)
External PI Controller or manual control
(Par. 1-00: Open loop)
Sleep mode
Wake up
Sleep mode
Wake up
No Flow detection (pumps only)
Yes
Yes (except manual setting
of speed)
Low speed detection
Yes
Yes
External signal
Yes
Yes
Pressure/Temperature (transmit-
ter connected)
Yes
No
Output frequency
No
Yes
NB!
Sleep Mode will not be active when Local Reference is active (set speed manually by means of arrow buttons on the Local Control
Panel). See Par. 3-13,
Reference Site
.
Does not work in Hand-mode. Auto set-up in open loop must be carried out before setting input/output in closed loop.
22-40 Minimum Run Time
Range:
Function:
10 s
*
[0 - 600 s]
Set the desired minimum running time for the motor after a Start command (digital input or Bus) before entering
Sleep Mode.
22-41 Minimum Sleep Time
Range:
Function:
10 s
*
[0 - 600 s]
Set the desired minimum time for staying in Sleep Mode. This will override any wake up conditions.
3. Parameter Description
VLT
®
HVAC Drive Programming Guide
180
MG.11.C5.02 - VLT
®
is a registered Danfoss trademark
3