English
8
WILO SE 10/2021
NOTE: If the pump is being operated with the
wrong direction of rotation, a reduction in the
volume flow occurs.
If the direction of rotation is incorrect, 2 phases of
the mains connection (in the switchbox or on the
contact maker) have to be changed.
8.2 Commissioning
CAUTION! Danger of material damage!
Danger of damage to the mechanical seal. Never
allow the pump to run dry, even for a short time.
• Check all electrical connections, the electrical
protection, and fuses once again.
• Check the current consumption intermittently
and compare with the values on the name plate.
Never exceed the motor nominal current (In)
permissible for the motor (see name plate)
• Check the voltage with the motor running.
Permissible tolerance: ± 10 %.
• Vent the pressure ports in order to avoid pressure
surge during start-up.
• Close the valves during initial commissioning to
minimise fluid hammers due to start-up and
briefly increased amounts of sand in the fluid (dur-
ing initial use of the well).
• Do not start the pump more than 20 times an hour
(danger of overheating).
• Ensure that the pump is only operated within the
area printed in bold of the curve illustrated in the
catalogue. Under no circumstances operate the
pump to the right or left beyond the curve area
printed in bold.
• Never operate the pump for an extended period
with the valve closed.
8.3 Fluid temperature
Submersible pumps may, at nominal current, be
operated between min. 3 °C and max. 30 °C. In
order to guarantee effective cooling, the circula-
tion flow velocity of the cooling water over the
surface of the motor must be at least 10 cm/sec.
for 4" motors and 16 cm/sec. for 6" motors.
In order to guarantee motor cooling at higher
temperatures, the flow rate must be reduced pro-
portionally to the motor power (see table above)
NOTE: Do not operate the motors where the fluid
temperature exceeds 55 °C!
8.4 Checking and correcting the motor filling level
(Fig. 6)
The checking and correction of the filling level of
the motor fluid must be performed by qualified
personnel. The TWI4 motor may only be refilled by
the manufacturer.
• Lie the motor horizontally with opening (C) fac-
ing upwards
• Insert the pin gauge into the drilling (E) on the
diaphragm housing and check the diaphragm
level (D) -see table 1-. The notch on the pin
gauge must be level with the outer edge of the
drilling.
• If the water lever is too low, remove the filter (C)
(for TWI6 only).
• Place a filled syringe on the valve and inject
water into the motor.
• To vent the valve, briefly press the valve in with
the pin gauge until water that is free of bubbles
emerges. Caution over pressure!
• Continue filling with water until the diaphragm
level (D) has been reached.
• Re-insert the filter (C).
9 Maintenance
Maintenance and repairs may only be carried out
by qualified experts!
DANGER! Risk of fatal injury!
When working on electrical equipment, there is
a risk of a fatal shock.
• The pump should be electrically isolated and
secured against unauthorised switch-on during
any maintenance or repair work.
• Any damage to the connecting cable should
always be rectified by a qualified electrician
only.
NOTE: No particular maintenance necessary dur-
ing normal operation.
Min. required volume flow for motor cooling up to a water
temperature of 30 °C
Inside diameter of the
side of the well or cooling
jacket pipe
4" motor
6" motor
102 mm (4")
0.30 m³/h
--
127 mm (5")
1.60 m³/h
--
152 mm (6")
3.00 m³/h
2.10 m³/h
178 mm (7")
4.60 m³/h
6.00 m³/h
203 mm (8")
6.90 m³/h
10.30 m³/h
Fluid temperature
Water tempera-
ture
Adjustment (%) of the nominal cur-
rent from 0.37 kW to 5.5 kW
35 °C
95 %
40 °C
95 %
45 °C
90 %
50 °C
80 %
55 °C
70 %
Type of motor
Test dimen-
sion (D)
Tolerance
4" 10 mm
+/-
2 mm
6" (AISI 304 SS)
59 mm
+/- 2 mm
6" (AISI 316 SS)
19 mm
+/- 2 mm
