Installation and operating instructions Wilo-Rexa FIT
39
INSTALLATION
English
3.
Starting up the pump: about 1-3 h
• As described in the “Commissioning” section
5.3.4. Stationary dry well installation
In this installation type, the operating space is di-
vided: collector tank and machine room. The fluid
is collected in the collector tank and the pump
is installed in the machine room. The operating
space must be blocked out as per the manufac-
turer's configuration or planning guide. The pump
is connected to the suction- and pressure-side
pipe system at the specified point in the machine
room. The pump itself is not immersed in the
fluid.
The suction- and pressure-side pipe system must
be self-supporting, i.e. it may not be supported
by the pump. In addition, the pump connection
to the pipe system must be free of stress and
vibrations. We therefore recommend using elastic
connection pieces (compensators).
The following operating parameters must be
observed for dry well installation.
•
The
max. fluid temperature and ambient tem
-
perature
is
40 °C
.
•
Details for "Non-immersed operating mode"
The pump is not self-priming so that hydraulics
housing must be completely filled with the flu
-
id. The minimum level in the collector tank must
be at the same height as the upper edge of the
hydraulics housing.
BEWARE of burns!
The housing parts can heat up to well above
40°C. There is a risk of burns! After switch
-
ing it off, let the pump cool down to ambient
temperature.
Fig. 4.: Stationary dry well installation
1 Collector tank
5 Compensator
2 Machine room
6
Pump
3 Gate valve
7 Min. water level
4 Non-return valve
8 Dry-running protection
Work steps
1.
Installing the pump: about 3-5 h
•
Check that the pipe system is secured firmly.
• Secure lifting equipment to the pump with
a shackle, lift the pump and then lower slowly
on to the pipe system.
• When lowering the pump, take care of the
power supply cables.
• When the pump is resting on the piping, fasten
the pump to the pipe system on the suction
and pressure sides.
• Route the power supply cables in accordance
with local requirements.
• Have the electrical connections made by
a qualified electrician.
2. Installing optional accessories, such as dry-run-
ning protection or level controls.
3.
Starting up the pump: about 2-4 h
• As described in the “Commissioning” section
•
Open slide valves on suction and pressure sides.
• Vent the pressure pipe.
5.3.5. Level control
Fill levels can be determined using the level
control system, meaning the pump is switched on
and off automatically. The fill level can be record
-
ed using float switches, pressure and ultrasound
measurements or electrodes.
Note the following information:
•
When using float switches, ensure that they can
move freely in the operating area!
•
The water level must not fall below the minimum!
•
The maximum switching frequency may not be
exceeded!
•
If the fill levels fluctuate strongly, then a level
control should be made on two test points as
standard. This means larger differential gaps are
reached.
Installation
The "A" version of the FIT series is equipped with
a float switch for level measurement. In this con
-
figuration a contact is opened or closed depend
-
ing on the angle of inclination of the float switch.
The switching level is determined by the cable
length of the float switch.
When using a separate level control device, please
refer to the installation and operation instruc-
tions supplied with the level control device when
installing it.
Observe the information on the maximum
switching frequency and the minimum water
level!
5.4. Dry-running protection
To ensure the necessary cooling, the pump must
be immersed when in operation, depending on
the operating mode. In addition, make sure that
no air enters the hydraulics housing.
The pump must therefore always be immersed
in the fluid up to the top edge of the hydraulic
housing or, if applicable, up to the top edge of
the motor housing. For optimum operational
reliability, we recommend installing a dry-running
protection system.
Correct running is ensured by float switches or
electrodes. The float switch or electrode is fixed
in the sump and switches off the pump when the
water level falls below the minimum coverage
level. If the dry-running protection only includes
one floater or electrode and the fill levels deviate
significantly, then the pump may turn on and
off constantly! This can result in the maximum
number of motor activations (switching cycles)
being exceeded.
5.4.1. Remedies for avoiding excessive switching
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.
