Xylem AquaForce Variable Speed Package System - Manual (Page 25)

The pump station experiences excessive vibration
Cause Remedy
The motor, pump, or piping is loose. Make sure that all fasteners and components are
properly tightened.
Pump station vibration dampers are missing or
improperly installed.
Check for properly installed pump station vibration
dampers.
Pumps are running off their design curve. Check the application. Is the system running in an open
discharge condition (excessive flow rate)? For example, is
the system filling a large irrigation line for the first time
of the season?
Air or gases are present in the pumped liquid. Check water supply lines and tanks. Check for air or gases
in liquid. Bleed the lines.
Discharge piping is plugged. Check discharge piping/valves. Could the piping be
plugged? Could the pump be plugged? Are the isolation
valves open? Clear any clogs.
Supply piping has excessive suction/lift conditions or
friction loss.
Check for excessive suction/lift conditions or friction loss
on supply piping.
The impeller is bound or worn. Take the pump to an authorized pump repair facility.
Pumps and pipes are not properly aligned. Correct the alignment between pumps and pipes.
The pump station does not shut down and no water is used
Cause Remedy
The pump station is in Hand or Manual mode. Put the system in the AUTO position.
The system pressure is set beyond capability of the
station.
Check the system set pressure. Is this duty point beyond
the capability of the pump station?
There are leaks or broken pipes. Check for broken pipes or leaks. Does the system
pressure decrease if the pump station is turned off?
The diaphragm tank is faulty. Check for a properly installed diaphragm tank. Has the
tank failed? Has the tank been charged to the proper
operating pressure before installation? (~10 psi below
the desired set point)
The pressure transducers are faulty. Check the pressure transducers. Does the actual
mechanical gauge pressure match the pressure
displayed on the VFDs and the PLC?
The VFDs are in Local mode. Put the VFDs in Remote mode.
A check valve is malfunctioning. Check for malfunctioning check valves. Does the system
hold pressure when the pump package is shut down?
Replace faulty valves.
The pump station cycles or hunts erratically
Cause Remedy
The pumps are oversized for the current demand. Check the application. Possibly increase the size of the
bladder tank for low demand situations.
The inlet pressure is fluctuating. Check the application. Possibly increase the size of the
bladder tank for low demand situations.
There are leaks or broken pipes. Check for broken pipes or leaks. Does the system
pressure decrease when the pump station is turned off?
Troubleshooting
AquaForce Variable Speed Package System Mechanical Installation, Operation, and Maintenance Manual 23