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

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6.4.6

Level control

6.4.7

Dry-running protection

6.5

Electrical connection

24
Installation and electrical connection
4. Connect pump to the pipe system. NOTICE! Ensure the connection is free of stress
and vibrations. If required, use plastic connection pieces (compensators).
5. Loosen the lifting gear from the pump.
6. Have the power supply cables installed in the machine room by a qualified electrician.
▶ Pump is installed, the qualified electrician can carry out the electrical connection.
DANGER
Risk of explosion due to incorrect installation!
If the level control is installed within a potentially explosive area, the signal transmitter
must be connected via an Ex cut-off relay or a Zener barrier. There is a risk of explosion if
connected incorrectly! Connection must be carried out by a qualified electrician.
Using a level control device the current fluid levels can be determined and the pump auto-
matically switched on and off depending on the fluid level. The recording of the fluid level is
made here by various sensor types (float switches, pressure and ultrasound measurements
or electrodes). When using a level control device observe the following points:
▪ Float switches can move freely!
▪ The minimal permissible water level must not be undercut!
▪ The maximum switching frequency must not be exceeded!
▪ For strongly fluctuating fluid levels, a level control device with two measuring points is rec-
ommended. This means larger differential gaps are reached.
Dry-running protection must prevent the pump from being operated without fluid and air
from penetrating into the hydraulics. To do this the minimum permissible fluid level must be
determined using a sensor. As soon as the given limit value is reached, the pump must be
deactivated with a corresponding signal. Dry-running protection can expand existing level
control devices by an additional measuring point or work as a sole switch-off device. The
reactivation of the pump can take place automatically or manually depending on the system
security. For optimum operational reliability, the installation of a dry-running protection
system is recommended.
DANGER
Electrocution hazard!
Improper conduct when carrying out electrical work causes death due to electric shock!
Electrical work must be carried out by a qualified electrician in accordance with the local
regulations.
WILO SE 2019-02