Level Control; Dry-Running Protection; Electrical Connection - Wilo Rexa UNI Instrucciones De Instalación Y Funcionamiento

2. Lift the pump and lower it at the intended location
(chamber, pit).
3. Place the pump on a solid bearing surface. CAU-
TION! Sinking must be prevented!
4. Lay the pressure hose and fasten it to a certain point
(e.g. drainage). DANGER! Separation or movement of
the pressure hose can lead to (serious) injuries! Se-
curely attach the pressure hose to the outlet.
5. Lay the power supply cable properly. CAUTION! Do not
damage the power supply cable!
▶ The pump is installed, the qualified electrician can make
the electrical connection.
6.4.6

Level control

With a level control device, the current fill levels are de-
termined and the pump is switched on and off automati-
cally depending on the fill levels. Fill levels are recorded
by using different sensor types (float switches, pressure
and ultrasound measurements or electrodes). The fol-
lowing must be observed when using a level control
device:
▪ Float switches can move freely!
▪ The water level must not fall below the minimum per-
missible!
▪ The maximum switching frequency must not be ex-
ceeded!
▪ If the fill levels fluctuate strongly, a level control with
two measuring points is recommended. This makes it
possible to achieve larger differential gaps.
Use of attached float switch
The "A" version is equipped with a float switch. The
pump is switched on and off depending on the fill level.
The switching level is determined by the cable length of
the float switch.
Use of on-site level controls
When using an on-site level control device, refer to the
manufacturer's own installation and operating instruc-
tions for specifications on the installation.
6.4.7

Dry-running protection

Dry-running protection must prevent the pump from
operating without fluid and air from entering the hy-
draulics. The minimum permissible fill level must be de-
termined with the help of a signal transmitter. Once the
specified limit value is reached, the pump must be deac-
tivated with an appropriate signal. Dry-running protec-
tion can expand the available level controls by an addi-
tional measuring point or function as an independent
Installation and operating instructions Wilo-Rexa UNI
Installation and electrical connection
switch-off device. Depending on the system security,
the pump can be restarted automatically or manually. In-
stallation of dry-running protection is recommended for
optimum operational reliability.
6.5

Electrical connection

DANGER
Risk of death due to electrocution!
Improper conduct when carrying out electrical work
can lead to death due to electric shock! Electrical
work must be carried out by a qualified electrician in
accordance with the locally applicable regulations.
▪ The mains connection must match the specifications on
the rating plate.
▪ Power supply on mains side for three-phase current mo-
tors with clockwise rotating field.
▪ Lay the connection cable in accordance with the locally
applicable regulations and connect it according to the
wire assignment.
▪ Connect the monitoring devices and check their func-
tion.
▪ Earth the device properly in accordance with applicable
local regulations.
6.5.1 Fuse on mains side
Circuit breaker
The size and switching characteristics of the circuit
breakers must conform to the rated current of the con-
nected product. Observe local regulations.
Motor protection switch
Make provision for an on-site motor protection switch
for devices without a plug! The minimum requirement is
a thermal relay/motor protection switch with temper-
ature compensation, differential triggering and anti-re-
activation device in accordance with the local regula-
tions. In case of sensitive mains, make provision for the
installation on-site of other protective equipment (e.g.
overvoltage, undervoltage or phase failure relay, etc.).
Residual-current device (RCD)
Comply with the regulations of the local energy supply
company! The use of a residual-current device is recom-
mended.
If persons come into contact with the device and con-
ductive fluids, secure the connection with a residual-
current device (RCD).
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