Danfoss VLT HVAC Drive FC 131 Programming Manual page 160

VLT® HVAC Drive FC 131
Programming Guide
Dry-pump detection
If the pump has run dry (low power consumption-high speed), no-flow detection can also be used for detecting with both the inte-
grated PI controller and an external PI controller.
The 2 conditions for dry-pump signal are as follows:
• Power consumption below no-flow level.
• Pump running at maximum speed or maximum reference open loop, whichever is lowest.
The signal must be active for a set time (parameter 22-27 Dry Pump Delay) before the selected action takes place. Possible actions
can be selected from parameter 22-26 Dry Pump Function.
22-26 Dry Pump Function
Default value: [0] Off
Conversion index: -
Select desired action for dry pump operation.
-
For drives with constant speed bypass, if an automatic bypass function starts the bypass at persistent alarm conditions, disa-
ble the automatic bypass function when [2] Alarm or [3] Man. Reset Alarm is selected for the dry pump function.
Table 377: Option:
[0] Off This function is not active.
[1] Warning
The drive continues to run, but activates a warning (warning 93, dry pump). A drive digital output or a serial com-
munication bus can communicate the warning to other equipment.
[2] Alarm The drive stops running and activates an alarm (alarm 93, dry pump). A drive digital output or a serial communi-
cation bus can communicate the alarm to other equipment.
-
When this option is selected, do not set parameter 14-20 Reset Mode to [13] Infinite auto reset. Doing so
causes the drive to continuously cycle between running and stopping when a dry pump condition is de-
tected.
[3] Man. Re- The drive stops running and activates an alarm (alarm 93, dry pump). A drive digital output or a serial communi-
set cation bus can communicate the alarm to other equipment. If this option is selected and the dry pump condi-
Alarm
tion is detected, the drive can only be reset manually.
22-27 Dry Pump Delay
Default value: 10 s
Conversion index: 0
Set the delay before the action set in parameter 22-26 Dry Pump Function takes place if a dry-pump condition is detected.
Table 378: Range:
Min: 0 s
4.16.3 22-3* No-flow Power Tuning
Parameters for setting up low power detection for the no flow function.
160 | Danfoss A/S © 2022.05
Parameter type: Option
Data type: u_int8
N O T I C E
Parameter type: Range
Data type: u_int16
Max: 600 s
2-setup: All setups
Change during operation: True
N O T I C E
2-setup: All setups
Change during operation: True
Default value: 10 s
Parameters
AU370727746889en-000101 / 130R0994