Function Description; Operating Modes - Wilo Sub TWU 3 HS Serie Notice De Montage Et De Mise En Service

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Fig. 1: Description of the submersible pump
1 Cable
2 Suction piece
3 Motor housing
Fig. 2: Description of the external frequency converter
1 Inlet
2 Pressure connection
3.2.1 Hydraulics
Multistage hydraulics with radial impellers in
sectional construction. The hydraulics housing
and the pump shaft are made of stainless steel
and the impellers are made of Noryl. The con-
nection on the pressure side is designed as a
vertical threaded flange with a female thread and
integrated non-return valve.
The pump is not self-priming, i.e. the fluid
must flow in either automatically or with sup-
ply pressure and a minimum coverage must be
ensured at all times.
3.2.2 Motor
The motors used are all oil-filled three-phase
AC motor for direct starting on the frequency
converter. The motor housing is made of stainless
steel and has a shaft connection for 3" hydraulics.
The motor is cooled by the pumped fluid.
Therefore, the motor must always be operated
immersed. The limit values for maximum fluid
temperature and minimum flow velocity must be
adhered to.
The connection cable has free cable ends, is
longitudinally watertight and is connected to the
motor by a detachable plug.
3.2.3 Frequency converter
The frequency converter is either enclosed as an
external component (TWU 3-...-HS-ECP) or it is
integrated in the motor (TWU 3-...-HS-I).
Like the motor, the frequency converter is cooled
by the fluid. To do this, the external frequency
converter must be installed in the ascending pipe.
The internal frequency converter is cooled by the
surrounding fluid.
The frequency converter offers the monitoring
functions:
34
4 Hydraulics housing
5 Pressure connection
Internal frequency
6
converter
Control panel and
3
display
Monitoring
Undervoltage
Overvoltage
Short-circuit
Temperature (frequency converter)
Dry run
Leakage
The external frequency converter is not overflow-
proof! Note that the device has protection class
"IPX5" and only ever install it overflow-proof in
dry rooms!
3.2.4 Seal
The sealing between the motor and hydraulics is
achieved by a lip seal.

3.3 Function description

3.3.1 Version "HS-I"
In the "HS-I" version, the pump is switched on
and off via a separate switching system. After
it is switched on, the pump is accelerated to its
maximum speed via the integrated frequency
converter, pumping at full power. Frequency-de-
pendent control and pressure-dependent control
are not possible.
3.3.2 Version "HS-ECP"
The "HS-ECP" version is operated with an exter-
nal frequency converter. This both serves as a
separate control unit for the pump and it provides
a control function for constant pressure ("CP").
This function makes it possible to always ensure
the same pressure at the tap, regardless of the
volume flow.
The pump is controlled via the frequency con-
verter, where the set pressure is set. When water
is drawn from the tap, the frequency converter
switches the unit on. The frequency converter
uses the preset pressure to calculate the required
volume flow and it adjusts the motor speed ac-
cordingly. This enables a constant pressure at all
times at the tap.

3.4 Operating modes

3.4.1 Operating mode S1 (continuous duty)
The pump can operate continuously at the rated
load without exceeding the permissible tempera-
ture.
PRODUCT DESCRIPTION
HS-ECP HS-I
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WILO SE 05-2019 DIN A4