Technical information

Dry pump detection:
No Flow Detection can also be used for detecting if the
pump has run dry (low power consumption-high speed).
Can be used with both the integrated PI controller and an
external PI controller.
The condition for Dry Pump signal:
- Power consumption below no flow level
and
- Pump running at maximum speed or maximum
reference open loop, whichever is lowest.
The signal must be active for a set time (22-27 Dry Pump
Delay) before selected the action takes place.
Possible Actions to select (22-26 Dry Pump Function):
- 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 parameter group 22-3* for
proper operation!
22-22 Low Speed Detection
Option: Function:
[0] * Disabled
[1] 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].
22-23 No-Flow Function
Common actions for Low Power Detection and Low Speed
Detection (Individual selections not possible).
Option: Function:
[0] * Off
[1] Sleep Mode The frequency converter will enter Sleep Mode
and stop when a No Flow condition is
detected. See parameter group 22-4* for
programming options for Sleep Mode.
[2] 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.
[3] Alarm The frequency converter will stop running and
activate a No-Flow Alarm [A 92]. A frequency
converter digital output or a serial communi-
cation bus can communicate an alarm to
other equipment.
NOTE
Do not set 14-20 Reset Mode, to [13] Infinite auto reset,
when 22-23 No-Flow Function is set to [3] Alarm. Doing so
will cause the frequency converter to continuously cycle
between running and stopping when a No Flow condition
is detected.
NOTE
If the frequency converter is equipped with a constant
speed bypass with an automatic bypass function that starts
the bypass if the frequency converter 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.
Parameter Description
VLT
®
HVAC Drive Programming Guide
MG11CD02 - VLT
®
is a registered Danfoss trademark 149
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