en – Original Instructions
e-SHE, e-SHS
– Additional Installation, Operation and Maintenance Instructions 35
7.9 The unit produces excessive noise and/or vibrations
Increase the NPSH
3
available in the system
Anti-vibration joints not installed
Install anti-vibration joints on the suction and discharge sides of the
unit
Foreign bodies in the unit
Remove the foreign bodies
Motor bearings worn or faulty
Replace the motor bearings
The unit does not turn freely due to a mechanical fault
Send the unit to an authorised workshop for testing
7.10 The unit starts up too frequently (automatic start/stop)
Incorrect priming (there are air bubbles in the suction pipe or in the
unit)
Repeat the priming procedure
Check valve locked in closed or partially closed position
Foot check valve locked in closed or partially closed position
Replace the foot check valve
Starter (pressure switch, sensor, etc.) set incorrectly, or faulty
Adjust or replace the starter
•
no pre-charge, or
•
undersized, or
Pre-charge the expansion vessel, or
•
replace the expansion vessel with another suitable one, or
•
install an expansion vessel
Contact Xylem or the Authorised Distributor
7.11 The unit never stops (automatic start/stop)
The required flow rate is greater than the one expected
Reduce the required flow rate
Motor turns in the wrong direction
Check the direction of rotation and change it if necessary
Pipes, on-off valves or filter clogged with impurities
Starter (pressure switch, sensor, etc.) set incorrectly, or faulty
Adjust or replace the starter
The unit runs but there is little or no flow rate
See the section: The thermal overload protection triggers
3
Net Positive Suction Head
To Next Page
Loading...
