Danfoss VLT Programming Manual page 144

Parameter Description
- Warning
- Alarm
No Flow Detection must be enabled (22-23 No-Flow Function)
and commissioned (parameter group 22-3*, No Power
Tuning).
22-20 Low Power Auto Set-up
Start of auto set-up of power data for No-Flow Power tuning.
Option: Function:
[0] Off
*
[1] Enabled When set for Enabled, an auto set up sequence is
activated, automatically setting speed to approx. 50
and 85% of rated motor speed (4-13 Motor Speed
High Limit [RPM], 4-14 Motor Speed High Limit [Hz]).
At those two speeds, the power consumption is
automatically measured and stored.
Before enabling Auto Set Up:
1. Close valve(s) in order to create a no flow
condition
2. The frequency converter must be set for
Open Loop (1-00 Configuration Mode).
Note that it is important also to set
1-03 Torque Characteristics.
NOTE
Auto Set Up must be done when the system has reached
normal operating temperature!
NOTE
It is important that the 4-13 Motor Speed High Limit [RPM] or
4-14 Motor Speed High Limit [Hz] is set to the max. operational
speed of the motor!
It is important to do the Auto Set-up before configuring the
integrated PI Contoller as settings will be reset when
changing from Closed to Open Loop in 1-00 Configuration
Mode.
NOTE
Carry out the tuning with the same settings in 1-03 Torque
Characteristics, as for operation after the tuning.
22-21 Low Power Detection
Option: Function:
[0] Disabled
*
[1] Enabled If selecting Enabled, the Low Power Detection
commissioning must be carried out in order to set
the parameters in group 22-3* for proper
operation!
®
VLT HVAC Drive Programming Guide
22-22 Low Speed Detection
Option:
[0]
[1]
22-23 No-Flow Function
Common actions for Low Power Detection and Low Speed
Detection (Individual selections not possible).
Option:
[0]
[1]
[2]
[3]
NOTE
Do not set 14-20 Reset Mode, to [13] Infinite auto reset, when
22-23 No-Flow Functionis set to [3] Alarm. Doing so will cause
the drive to continuously cycle between running and
stopping when a No Flow condition is detected.
NOTE
If the drive is equipped with a constant speed bypass with an
automatic bypass function that starts the bypass if the drive
experiences a persistent alarm condition, be sure to disable
the bypass's automatic bypass function, if [3] Alarm is
selected as the No-Flow Function.
22-24 No-Flow Delay
Range:
10 s
®
MG.11.CB.02 - VLT is a registered Danfoss trademark
Function:
Disabled
*
Enabled Select Enabled for detecting when the motor
operates with a speed as set in 4-11 Motor Speed
Low Limit [RPM] or 4-12 Motor Speed Low Limit
[Hz].
Function:
Off
*
Sleep Mode The drive will enter Sleep Mode and stop when
a No Flow condition is detected. See parameter
group 22-4* for programming options for Sleep
Mode.
Warning The drive will continue to run, but activate a
No-Flow Warning [W92]. A drive digital output
or a serial communication bus can
communicate a warning to other equipment.
Alarm The drive will stop running and activate a No-
Flow Alarm [A 92]. A drive digital output or a
serial communication bus can communicate an
alarm to other equipment.
Function:
[1 - 600 s] Set the time Low Power/Low Speed must stay
*
detected to activate signal for actions. If
detection disappears before run out of the
timer, the timer will be reset.
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