Xylem 2 Pump Booster Sets GXS20, GMD20, GMY20 - Manual (Page 20)

11. Disposal
Proceed in compliance with local codes and regulations pertaining to disposal of waste, including packa-
ging materials.
10. Troubleshooting
DANGER
The maintenance and repair operations must be performed by qualified per-
sonnel.
Before servicing the set, disconnect the power supply and make sure there is
no pressure in the hydraulic components.
20
en
Problem
1. Set is off
2. Motor does not start
3. Frequent startups
and stops
4. The motor starts up
but it stops immedia-
tely
5. The motor runs but
no water is delivered
6. Pump leaks water
7. Too noisy
Cause
1. Power supply disconnected
2. Blown fuse
1. Power supply disconnected
2. Triggering of motor protector
3. Single-phase : motor thermal pro-
tector
4. Three-phase : automatic switch in
electric panel
5. Defective motor
1. Defective tank
2. I n c o r r e c t p r e s s u r e s w i t c h
adjustment
1. Incorrect tank precharge pressure
2. I n c o r r e c t p r e s s u r e s w i t c h
adjustment
1. No water on suction side or inside
pump
2. Air in suction piping or pump
3. Loss of pressure on suction side
4. Check valve jammed
5. Clogged pipe
6. Incorrect rotation of three-phase
motors
1. Defective mechanical seal
2. Undue mechanical stress on
pump
1. Water return when pumps stop
2. Cavitation
3. Pump rotation hindered
Solution
Connect power supply
Replace fuse
Connect power supply
Eliminate malfunction.
Single-phase: wait for automatic reset
Three-phase: Reset the automatic
switch
Repair/replace motor
Repair/replace tank
Increase the differential pressure or
the stop pressure
Check tank precharge
Increase the differential pressure or
the stop pressure
Fill the pump or suction piping / open
the on-off valves
Bleed the pump, check the suction
connections.
Check the NPSH and, if necessary,
modify the system
Clean the valve
Clean the pipe
Change direction of rotation
Replace the mechanical seal
Support the pipes
Check the check valve
Check suction
Check for undue mechanical stress
on pump