Xylem AquaForce Variable Speed Package System - Manual (Page 24)

Cause Remedy
The fuses are blown or breakers are tripped. Check circuit breaker and fuses.
Transducer isolation valves are closed. Make sure that the transducer isolation valves are in the
open position.
Automatic mode is faulty. Check to see if the pump can be run in Manual mode on
the PLC.
The impeller is bound. Check to see if you can turn the pump by hand. Check for
a bound impeller.
A pressure transducer is faulty. Replace faulty pressure transducers.
Motor wiring is loose. Make sure that motor wiring is securely connected.
Motor windings have lost insulation strength. Test the motor leads with a megger in order to check the
motor windings.
Variable speed drive is wired incorrectly. Check corresponding variable speed drive. Make sure
drive is wired correctly.
Motor is defective. Repair or replace motor.
The pumps run but do not build desired pressure
Cause Remedy
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?
Pumps are running at less than full speed. Check to see if the pumps are running at full speed. If
they are running less than full speed, they could be
experiencing electrical issues. Check the panel for power
status.
The inlet pressure does not match the project
specifications.
Check to see if the inlet pressure matches the project
specifications. Variations in inlet pressure can have
detrimental effects on performance.
A pipe is broken. Check for broken pipes.
The transducer isolation valves are closed. Check to be sure that the transducer isolation valves are
in the open position.
The NPSH is insufficient. Check the NPSH. Are proper flooded conditions or
positive pressure being delivered to the pump station?
Check for air in the supply lines. Check for properly filled
supply tanks (if applicable). Excessive suction lift or
piping losses will limit the life expectancy of the pumps.
The pump station has lost its prime. Check to be sure that the pump station has been primed
properly. Make sure that all pumps and components are
properly filled with water.
The pump rotation is incorrect. Check the pump rotation. Proper rotation is indicated on
the pump volute. (See the pump IOM.)
A suction or discharge valve is closed or clogged. Check the isolation valves and check valves. Are all
suction/discharge valves open? Could any valves be
plugged? Could the pumps be plugged?
The motor is not operating at the rated RPM. Check the voltage and amperage. Check for possible
phase loss to the motor.
The impeller is worn or plugged. Take the pump to an authorized pump repair facility.
The pump bearings are worn. Take the pump to an authorized pump repair facility.
Troubleshooting
22 AquaForce Variable Speed Package System Mechanical Installation, Operation, and Maintenance Manual