Problems, Causes And Remedies; Assembly - Disassembly - Wilo TWI 5-SE Mode D'emploi

9. Problems, causes and remedies

Problems
Pump does not start up
No output or a very low output
Very frequent starts of the pump
CAUTION! Possible damage of the pump
A common cause of faults is a silted-up or
choked pump. The pump without stand must
hang sufficiently high above the bottom of the
shaft that it is not possible for it to silt up.
On repeated trippings of the overload protector
it will be necessary to have the pump checked by
a specialist or by WILO customer services.
If no solution can be found, please contact your
plumbing and heating specialist or your nearest
Wilo Customer Service or representative.
WILO AG 10/2006
Causes
Inadequate voltage or voltage drop
Motor power cable break
Motor protection ON
Very low voltage
The suction strainer is obstructed
The valve is closed
The sense of rotation is not correct
(three-phase motor)
The non return valve is jammed in the
close position
No water or very low water level in well
Pressure gauge contactor difference too
low
Inadequate float set-up
Bladder tank capacity is tow low or
insufficiently inflated
The non return valve leaked
Remedies
Check voltage on start-up, an insuffi-
cient cable cross-section can cause a
voltage drop that prevents the motor
from operating normally
Measure the resistance between phases.
Re-assemble the pump if required and
check the cable
Check the current set on thermal relay
and compare it to the mentioned value
Important: if it trips repetitively, do not
insist (look at the cause). Forcing the unit
to operation can damage the motor (by
overheating) in a very short time limit
Check the power supply at the switch
box
Reassemble the pump, clear and clean it
Open the valve
Interchange the two phase wires inside
the switch box
Dismantle and clean the non return valve
Check this level ; it must be at least
0.15 m above the sieve pump (during
operating)
Increase the gap between shutdown and
start-up
Adjust float location to ensure an appro-
priate time between pump ON/OFF
Check and adjust pressures (ON/OFF)
Check tank inflation. This pressure must
be 0.3 bar less than the pump starting
pressure
Increase capacity with an additionnal
tank or change the tank
Clean or change the non return valve
10. Assembly – Disassembly
CAUTION! Be careful not to mix part.
Unplug the pump.
(see FIG. 9a and 9b)
11. Spart parts
Spare parts are ordered via a local specialist dea-
ler and/or Wilo customer service.
In order to avoid queries and incorrect orders,
make sure to mention all data indicated on the
rating plate when placing your order.
Subject to technical alterations!
English
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