Before Switching On - Wilo Sub TWU 3 Série Notice De Montage Et De Mise En Service

If other activation or deactivation pressures are
required, then these must be within the permissible
functional range of the pressure switch.
After the pressure values have been specified, pressure
must be applied to the diaphragm pressure vessel.
Applying pressure to the diaphragm pressure vessel
Check the vessel pressure and fill it using the valve,
when necessary. Required vessel pressure: Activation
pressure = -0.3 bar.
Pressure manometer
Cut off the supports on the manometer to establish
the required atmospheric pressure compensation.
Setting the pressure switch
Fig. 5: Adjusting screws
Adjusting screw for
1
deactivation pressure
The setting can only be made when sufficient pressure
has been applied to the system.
Functional principle for setting the activation/deacti-
vation pressure:
• Setting of the activation/deactivation pressure is made
by turning the corresponding adjusting screw.
• Turning the threaded nut clockwise reduces the pres-
sure.
• Turning the threaded nut counter-clockwise increases
the pressure.
If the required activation and deactivation pressure
have been defined and the diaphragm pressure vessel
has been filled correctly, then the activation and deac-
tivation pressure can be set as follows:
• Open the discharge-side shut-off device and a tap to
depressurize the system.
• Close the tap.
• Open the hood on the pressure switch.
• Turn both adjusting screws ("1" and "2") clockwise
without tightening them.
• Start the pump to build up the pressure.
• When the required deactivation pressure is reached
(see reading on manometer), switch off the pump.
• Turn the adjusting screw "1" counter-clockwise until
you hear a click.
• Open the tap to reduce the system pressure to the
desired activation pressure for the pump (see reading
on manometer).
• When the activation pressure is reached, close the tap
slowly.
• Turn the adjusting screw "2" counter-clockwise.
When a click is heard:
• Switch on the pump and check the settings by open-
ing and closing a tap.
• Carry out any fine-tuning of the settings according to
the functional principle described above.
When the settings are completed, close the hood on
the pressure switch and put the system into operation.
If no click is heard:
Installation and operating instructions Wilo-Sub TWU 3..., TWU 3-...-P&P
Adjusting screw for
2
activation pressure
• Check the operating point of the pump and the pres-
sure applied to the diaphragm pressure vessel (required
vessel pressure: activation pressure = -0.3 bar).
• If necessary, select a new activation and deactivation
pressure and set the pressure on the diaphragm pres-
sure vessel again accordingly.
• Repeat the setting procedure until the desired system
functions have been established.
6.5 Startup
The work area of the unit is not a recreational
area and is to be kept free of persons! No per-
sons are allowed in the work area during switch-
ing on and/or during operation.
Before switching on for the first time, the installation
must be checked as described in the "Installation"
chapter and an isolation check must be carried out
according to the "Maintenance" chapter.
When using switching devices and/or plugs, the corre-
sponding IP protection classes must be observed.

6.5.1 Before switching on

The following points must be checked before switch-
ing on the submersible motor pump:
• Cable guidance – no loops, slightly taut.
• Check the temperature of the pumped liquid and the
submersion depth – see technical data.
• The product machine is fixed securely – vibration-free
operation must be assured.
• The accessories – pedestal, cooling jacket etc. are
securely fixed.
• The suction chamber of the pump sump and the pipe-
lines must be completely free of dirt.
• Flush out the pipeline and the product before connect-
ing them to the supply network.
• Carry out an insulation check. For details on this, see
the "Maintenance" chapter.
• The hydraulic housing must be flooded, i.e. it should be
completely full of fluid, with no air in it at all. Bleeding
can be carried out using a suitable bleeding device in
the system, or, if available, with bleeder screws on the
discharge port.
• The sliders on the pressure side should be half opened
during commissioning so that the pipeline can be bled.
• You can use an electrically actuated check valve to
reduce or prevent water impact. The unit can be
switched on in a throttled or closed slider position.
However, do not operate for long periods (> 5
minutes) with the slider closed or nearly closed,
and do not run the machine dry.
• Check all level control and dry-run protection systems.
6.5.2 After starting up
The rated current is briefly exceeded during the start-
up procedure. Once the start-up procedure has com-
pleted, the operating current may no longer exceed the
rated current.
If the motor does not start immediately after the unit
is switched on, it must be switched off without delay.
The start pauses specified in the "Technical data"
chapter must be adhered to before starting up again. If
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