Electrical Connection - Wilo Rexa CUT GI Instrucciones De Instalación Y Funcionamiento

6.4.5 Level control
6.4.6 Dry-running protection
6.5

Electrical connection

6.5.1 Line-side fuse protection
Installation and operating instructions Wilo-Rexa CUT GI
Installation and electrical connection
▶ Pump is installed, the qualified electrician can carry out the electrical connection.
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.
NOTICE
Attaching the additional rating plate
An additional rating plate is supplied with the pump. Attach this rating plate permanently
to the switchgear or switch cabinet.
▪ The mains connection must match the specifications on the rating plate.
▪ Power supply on the mains side for three-phase current motors with clockwise rotating
field.
▪ Lay the connection cable in accordance with the locally applicable regulations and connect
it according to the wire assignment.
▪ Connect monitoring devices and check function.
▪ Carry out earthing properly according to the local regulations.
Circuit breaker
The size and switching characteristics of the circuit breakers must conform to the rated cur-
rent of the product connected. Observe the locally applicable regulations.
Motor protection switch
For products supplied without a plug, a motor protection switch must be installed on-site.
The minimum requirement is a thermal relay/motor protection switch with temperature
compensation, differential triggering and an anti-reactivation device, in accordance with lo-
cal regulations. Further protection devices (e.g. overvoltage, undervoltage, or phase-failure
relay etc.) must be provided on-site for sensitive power supplies.
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