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 (
) before selected the action takes place.
Possible Actions to select (
):
-
Warning
-
Alarm
No Flow Detection must be enabled (
) 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 (
). 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 (
Note that it is important also to set
.
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
NOTE
Carry out the tuning with the same settings in
, 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
or
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 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.
[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 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.
Parameter Description
VLT
®
HVAC Drive Programming Guide
148
MG.11.CC.02 - VLT
®
is a registered Danfoss trademark
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