en - Original instructions
bearings is recommended. The bearings must be re-
placed after 25000 operating hours or according to
the motor supplier maintenance instructions, which-
ever is shorter.
Motor with regreasable bearings
Follow motor supplier maintenance instructions.
6.2 Inspection checklist
Check the mechanical
seal
Check for quiet running
6.3 Disassemble and replace the pump
parts
For more information about spare parts and assem-
bly and disassembly of the pump, see our website.
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
The thermal protector
incorporated in the
pump (if any) has trip-
ped.
The protective device
against dry running has
tripped.
The electric pump starts, but the thermal protection
trips a varying time after.
Cause
There are foreign objects
(solids or fibrous sub-
stances) inside the pump
which have jammed the
impeller.
The pump is overloaded
because it is pumping liq-
uid that is too dense and
viscous.
The pump runs but delivers too little or no liquid.
Cause
Remedy
The pump is clog-
Contact the Sales and Service
ged.
Department.
20
Check for leakage of the
mechanical seal. Re-
place the mechanical
seal if leakage is found.
Check frequently for qui-
et running of the pump
with vibration measure-
ments tools.
Remedy
Wait until the pump has
cooled down. The thermal
protector will automatical-
ly reset.
Check the liquid level in
the tank, or the mains
pressure.
Remedy
Contact the Sales and
Service Department.
Check the actual power
requirements based on
the characteristics of the
pumped liquid and then
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
There is no power
supply.
The thermal protector
incorporated in the
pump (if any) has trip-
ped.
The thermal relay or
motor protector in the
electric control panel
has tripped.
The protective device
against dry running
has tripped.
The fuses for the
pump or auxiliary cir-
cuits are blown.
7.3 The electric pump starts, but
the thermal protector trips or the
fuses blow immediately after
Cause
The power supply ca-
ble is damaged.
The thermal protection
or fuses are not suited
for the motor current.
The electric motor is
short circuit.
The motor overloads.
7.4 The electric pump starts, but
the thermal protector trips or the
fuses blow a short time after
Cause
The electrical panel is situ-
ated in an excessively
heated area or is exposed
to direct sunlight.
The power supply voltage
is not within the working
limits of the motor.
A power phase is missing. Check the
Remedy
• Restore the power sup-
ply.
• Make sure all electrical
connections to the pow-
er supply are intact.
Wait until the pump has
cooled down. The thermal
protector will automatically
reset.
Reset the thermal protec-
tion.
Check the:
• liquid level in the tank,
or the mains pressure
• protective device and its
connecting cables
Replace the fuses.
Remedy
Check the cable and re-
place as necessary.
Check the components
and replace as necessary.
Check the components
and replace as necessary.
Check the operating condi-
tions of the pump and re-
set the protection.
Remedy
Protect the electrical
panel from heat source
and direct sunlight.
Check the operating
conditions of the motor.