Dry-Running Protection; Electrical Connection - Wilo Sub TWU 3 High Speed Einbau- Und Betriebsanleitung

INSTALLATION
When installed horizontally, the pipe and unit are
mounted separately. Make sure that the discharge
port of the unit and the pipeline are level.
1. Drill the fastening holes for the supports on the
floor of the operating area (container/reservoir).
You will find specifications for the anchor bolts,
distances between holes and their sizes in the
corresponding instructions. Make certain that
the screws and plugs are sufficiently stable.
2. Fasten the supports to the floor and bring the
pump into the correct position using suitable
hoisting gear.
3. Fasten the pump to the supports using the sup-
plied fastening materials. Ensure that the name
plate points upwards!
4. Once the unit is firmly mounted, you can install
the piping system or connect a piping system
which is already in place. Ensure that the dis-
charge ports are level.
5. Connect the discharge pipe to the discharge port.
The threaded joint must be sealed. Please note
that the pipe system is mounted so that there is
no vibration or tension (use elastic connection
pieces, when necessary).
6. Lay the cables in such a manner that no-one
(maintenance personnel etc.) will be endangered
by them at any time (operation, quick repairs). Do
not damage the power supply lines. The electrical
connection must be carried out by an authorized
technician.
5.4.4. installation of the external frequency converter
Fig. 4.: Description
1 Intake
2 Discharge port
The frequency converter is fitted directly in the
pipeline so that it is cooled during operation by
the pumped liquid.
Note the following:
• The frequency converter is not flood-proof and
must therefore be fitted in a dry environment
(protection class IP X5).
• The electrical connection and all settings are
made directly on the frequency converter.
They must therefore be freely accessible.
• When installing, pay attention to the flow
d irection. Observe the flow direction arrow
on the housing of the frequency converter.
NoTE:
The size of the discharge and intake port on
the frequency converter is G 11/4 and the size
of the discharge port on the pump is Rp 1.
Depending on the discharge pipe after the
frequency converter, the customer must
provide 1 or 2 adapters.
Installation and operating instructions Wilo-Sub TWU 3/High Speed
3 Flow direction arrow

5.5. Dry-running protection

Submersible motor pumps are cooled by the
pumped fluid. The motor must therefore always
be submerged. Also make sure that no air enters
the hydraulic housing. The pump must therefore
always be submerged in the pumped liquid up
to the top edge of the hydraulic housing. For
optimum reliability, we recommend installing
a dry-run protection system.
Correct running is ensured by electrodes or level
sensors. The level sensor or electrode is fixed in
the borehole/basin and switches off the machine
when the water level falls below the minimum
coverage level.
If the fill levels fluctuate strongly, there is a dan-
ger that the unit will turn on and off constantly!
This can result in the maximum number of mo-
tor start-ups (switching cycles) being exceeded
and the motor overheating.
The TWU 3-...-HS-ECP has integrated dry-run-
ning protection, on the TWU 3-...-HS-I this must
be provided by the customer.
5.5.1. Corrective measures for avoiding excessive
switching cycles
Manual reset—The motor is switched off when
the water level falls below the minimum cover-
age level and switched back on when a sufficient
water level is reached.
Separate reactivation point—A second switch-
ing point (additional electrode) is used to obtain
a sufficient difference between the activation
and deactivation points. This prevents constant
switching. This function can be put into effect
with a level control relay.

5.6. Electrical connection

ELECTRoCUTioN hazard!
incorrect electrical connections can cause
fatal electric shocks. Electrical connections
may only be carried out by a qualified elec-
trician who is approved by the local power
supplier, in accordance with locally applicable
regulations.
• The mains current and voltage must be as stated
on the name plate.
• Connect the power supply cable in accordance
with the applicable standards and regulations
and according to the wire assignment.
• Any available monitoring equipment, e.g. for
the motor temperature, must be connected
and tested to ensure that it is working properly.
• Ground the unit properly.
Units that are permanently installed must be
grounded in compliance with nationally applica-
ble standards. If a separate grounding conductor
is available, it must be connected to the marked
hole or grounding terminal (;) using a suitable
screw, nut, toothed washer and flat washer. The
cross section of the cable for the grounding con-
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