Xylem FHF SHF - Manual (Page 23)

A) Supply electrical power
B1) Replace the fuses with suit-
able ones
B2) Repair the motor or replace
the cable
C) Reset the protector (if it steps in
again, see problem 4)
A) Disassemble the pump
B) Fill the pump with liquid after hav-
ing checked the seal of the suction
pipe and foot valve. Also check
the integrity of the mechanical
seal.
C) Reduce the suction lift.
Use a larger diameter pipe.
Flush the foot valve.
Replace the foot valve with a big-
ger one
D) Switch two leads in the terminal
board or starter
A) Choke the delivery
- See probable cause 2C
B) Replace the bearings
C) Clean
D) Set to the rated current
E) Close the delivery valve until the
flow rate returns to the rated value
F) Determine the actual power re-
quired and then replace the motor
en
23
8. Fault finding chart
PROBLEM PROBABLE CAUSE POSSIBLE REMEDIES
1. The pump does not
start
2. The pump does not
deliver or delivers a re-
duced or irregular flow
3. The pump vibrates
and is noisy
4. The overload protector
steps in:
- accidentally
- systematically
A) No power supply
B) Blown fuses:
B1) because they are inadequate
(blowing current too low)
B2) motor or supply cable are dam-
aged
C) Overload protection previously ac-
tivated
A) The rotating part is partially or
completely obstructed (generally
the impeller is obstructed by for-
eign objects)
B) The pump is not primed: inade-
quate filling or defective suction
pipe or foot valve seal (Warning!
The mechanical seal could have
suffered serious damage)
C) Excessive suction lift and/or flow
resistance in the suction pipe
D) Incorrect rotation direction
A) The pump is cavitating
B) Worn motor or support bearings
C) Foreign bodies between fixed and
rotating parts of pump
D) The unit is badly aligned
E) The elastic element must be re-
placed
A) See 3B
B) See 3C
C) Temporary lack of a phase
D) Incorrect setting
E) Pump delivery is higher than rated
delivery
F) Dense viscous liquid
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