Dry-Run Protection - Wilo Sub TWU 4 Serie Instrucciones De Instalación Y Funcionamiento

English
This installation type is only permitted when used
together with a cooling jacket. The unit is installed
directly in the water tank/reservoir/container and
flanged onto the discharge pipe. The cooling jacket
supports must be mounted at the distances specified
to prevent the unit from distorting.
The connected pipeline must be self-supporting,
i.e. it may not be supported by the product.
When installed horizontally, the pipe and unit are
mounted separately. Make sure that the discharge port
of the unit and the pipeline are level.
On this type of installation, the product must be
installed with a cooling jacket.
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 product
into the correct position using a suitable hoisting gear.
3 Fasten the product to the supports using the supplied
fastening materials. Ensure that the type plate points
upwards!
4 Once the unit is firmly mounted, you can install the
piping system or flange-connect a piping system
which is already in place. Ensure that the discharge
ports are level.
5 Connect the discharge pipe to the discharge port. A
seal must be placed between the flanges of the pipe-
line and the unit. Tighten the fastening bolts in a cross
pattern to avoid damaging the seal. Please note that
the pipe system is mounted so that there is no vibra-
tion or tension (use elastic connection pieces, when
necessary).
6 Lay the cables in such a manner that no-one (mainte-
nance 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.
5.4.5 Inserting the Plug&Pump systems
Fig. 4: Installation
1 Unit
2 Motor connection cable
3 Holding cable
4 Screw connection 1¼"
5 Screw connection 1"
6 Fluid control
* Kit pre-assembled at the factory, consisting of:
• 18 l diaphragm pressure vessel
• Pressure manometer
• Shut-off valve
38
7 Mains supply
8 Pressure switching kit*
9 T-piece
Filling valve for dia-
10
phragm pressure vessel
Supports on pressure
11
manometer
TWU...-P&P/FC (Economy 1)
For fixed pipes or flexible hose connections with 1¼"
nominal width (40 mm diameter).
In case of hose connections, the supplied union nuts
are used. These are installed as follows:
• Loosen the bolted connection and leave it in place on
the thread whilst inserting the hose.
• Push the hose through the bolted connection up to the
stop.
• Tighten the bolted connection using the pipe wrench.
In case of a fixed pipe connection, the supplied 1¼"
union nut is used for the pump/pipe connection and
the 1¼" x 1" reducer for connecting to the fluid con-
trol.
TWU...P&P/DS (Economy 2)
For fixed pipes with 1¼" nominal width (40 mm diame-
ter).
The system is pre-assembled. Only the T-piece needs
to be attached to the assembly.
Please ensure that the support on the pressure
manometer is set to the highest position!

5.5 Dry-run protection

Make sure that no air enters the hydraulic housing. The
product must therefore always be submerged in the
pumped liquid up to the top edge of the pump hous-
ing. For optimum reliability, we recommend installing a
dry-run protection system.
Correct running is ensured by float switches or elec-
trodes. The float switch or electrode is fixed in the
shaft and switches off the machine when the water
level falls below the minimum coverage level. If the dry-
run protection is put into effect with only one float or
electrode whilst the filling levels fluctuate strongly,
there is a danger that the unit will turn on and off con-
stantly!
This can result in the maximum number of motor
start-ups (switching cycles) being exceeded and
the motor overheating.
5.5.1 Corrective measures for avoiding excessive switch-
ing cycles
Manual reset - The motor is switched off when the
water level falls below the minimum coverage level and
switched back on when a sufficient water level is
reached.
Separate reactivation point - A second switching
point (additional float or electrode) is used to obtain a
sufficient difference between the activation and deac-
tivation points. This prevents constant switching. This
function can be put into effect with a level control
relay.
WILO SE 10/2011 V4.1WE