3 inspection checklist, 4 disassemble and replace the pump parts, 7 troubleshooting – Xylem e-NSC, e-NSCF, e-NSCC User Manual
Page 19: 1 troubleshooting for users, If not, refer to, Troubleshooting

6.3 Inspection checklist
Check the coupling
Check the flexible elements of the
coupling. Replace the relevant
parts if there is any sign of wear
and check the alignment.
Check the mechanical seal
Check for leakage of the mechani-
cal seal. Replace the mechanical
seal if leakage is found.
Checking the bearing seals
Check correct seating of axial seal
rings mounted on the shaft. Only
gentle contact of the sealing lip
shall be established.
6.4 Disassemble and replace the pump parts
For more information about spare parts and assembly and disassem-
.
See the Repair and Assembly Instructions which are available for
download from our homepage.
7 Troubleshooting
7.1 Troubleshooting for users
The main switch is on, but the electric pump does not start.
Cause
Remedy
The thermal protector incorpo-
rated in the pump (if any) has
tripped.
Wait until the pump has cooled
down. The thermal protector will au-
tomatically reset.
The protective device against
dry running has tripped.
Check the liquid level in the tank, or
the mains pressure.
The electric pump starts, but the thermal protection trips a varying time
after.
Cause
Remedy
There are foreign objects (solids or
fibrous substances) inside the
pump which have jammed the im-
peller.
Contact the Sales and Service
Department.
The pump is overloaded because
it is pumping liquid that is too
dense and viscous.
Check the actual power require-
ments based on the characteris-
tics of the pumped liquid and then
contact the Sales and Service
Department.
The pump runs but delivers too little or no liquid.
Cause
Remedy
The pump is clogged. Contact the Sales and Service Department.
The troubleshooting instructions in the tables below are for installers
only.
7.2 The main switch is on, but the electric
pump does not start
Cause
Remedy
There is no power supply.
• Restore the power supply.
• Make sure all electrical connec-
tions to the power supply are in-
tact.
The thermal protector incorpo-
rated in the pump (if any) has
tripped.
Wait until the pump has cooled down.
The thermal protector will automati-
cally reset.
The thermal relay or motor
protector in the electric control
panel has tripped.
Reset the thermal protection.
Cause
Remedy
The protective device against
dry running has tripped.
Check the:
• liquid level in the tank, or the
mains pressure
• protective device and its con-
necting cables
The fuses for the pump or
auxiliary circuits are blown.
Replace the fuses.
7.3 The electric pump starts, but the thermal
protector trips or the fuses blow immediately
after
Cause
Remedy
The power supply cable is
damaged.
Check the cable and replace as nec-
essary.
The thermal protection or fuses
are not suited for the motor
current.
Check the components and replace
as necessary.
The electric motor is short cir-
cuit.
Check the components and replace
as necessary.
The motor overloads.
Check the operating conditions of the
pump and reset the protection.
7.4 The electric pump starts, but the thermal
protector trips or the fuses blow a short time
after
Cause
Remedy
The electrical panel is situated in an
excessively heated area or is ex-
posed to direct sunlight.
Protect the electrical panel from
heat source and direct sunlight.
The power supply voltage is not
within the working limits of the mo-
tor.
Check the operating conditions
of the motor.
A power phase is missing.
Check the
• power supply
• electrical connection
7.5 The electric pump starts, but the thermal
protector trips a varying time after
Cause
Remedy
There are foreign objects (sol-
ids or fibrous substances) in-
side the pump which have jam-
med the impeller.
Contact the local sales and service
representative.
The pumps delivery rate is
higher than the limits specified
on the data plate.
Partially close the on-off valve down
stream until the delivery rate is equal
or less than the limits specified on
the data plate.
The pump is overloaded be-
cause it is pumping liquid that
is too dense and viscous.
Check the actual power requirements
based on the characteristics of the
pumped liquid and replace the motor
accordingly.
The motor bearings are worn.
Contact the local sales and service
representative.
7.6 The electric pump starts, but the system's
general protection is activated
Cause
Remedy
A short circuit in the electrical system.
Check the electrical system.
en - Translation of the original instructions
e-NSC Installation, Operation, and Maintenance Manual
19