Wilo Sub TWI 5, Installation And Operating Instructions Manual

Page: 19 / 104

19 WILO SE 04/2013
English
9. Problems, causes and remedies
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.
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
nameplate when placing your order.
Subject to technical alterations!
Problems Causes Remedies
Pump does not start up Inadequate voltage or voltage drop Check voltage on start-up, an insuffi-
cient cable cross-section can cause a
voltage drop that prevents the motor
from operating normally.
Motor power cable break Measure the resistance between phases.
Re-assemble the pump if required and
check the cable.
Motor protection ON 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.
Pump does not switch on/off Float switch blocked or cannot move
freely Check float switch and ensure mobility.
No output or a very low output Very low voltage Check the power supply at the switch
box.
The suction strainer is obstructed Reassemble the pump, clear and clean it.
The valve is closed Open the valve.
The direction of rotation is not correct
(three-phase motor) Interchange the two phase wires inside
the switch box.
The non return valve is jammed in the
close position Dismantle and clean the non return
valve.
No water or very low water level in well Check this level ; it must be at least
0.15 m above the sieve pump (during
operating).
Air in the pump To carry out a hole Ø 3 mm on the
discharge pipe (Siehe Bild. 3, pos. 13)
between the pump and non-return valve.
Very frequent starts of the pump Pressure gauge contactor difference too
low Increase the gap between shutdown and
start-up.
Inadequate float set-up Adjust float location to ensure an appro-
priate time between pump ON/OFF.
Bladder tank capacity is tow low or
insufficiently inflated 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.
The non return valve leaked Clean or change the non return valve.