Electrical Connection; Fuse On Mains Side; Checking The Insulation Resistance Of The Motor Winding; Test The Resistor Of The Temperature Sensor - Wilo -Rexa FIT Instrucciones De Instalación Y Funcionamiento

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).
Installation and operating instructions Wilo-Rexa FIT
Installation and electrical connection
6.5.2 Maintenance tasks
Carry out the following maintenance tasks prior to in-
stallation:
▪ Check the insulation resistance of the motor winding.
▪ Test the resistance of the temperature sensor.
▪ Test the resistance of the pencil electrode (optionally
available).
If the measured values differ from the specifications:
▪ Moisture may have penetrated into the motor or the
connection cable.
▪ The monitoring device may be defective.
Contact customer service in the event of a fault.
6.5.2.1 Checking the insulation resistance of the motor wind-
ing
Use an insulation tester to measure the insulation resist-
ance (measuring voltage = 1000 V). Observe the follow-
ing values:
▪ At the time of initial commissioning: Insulation resistance
may not be less than 20 MΩ.
▪ For further measurements: Value must be greater than
2 MΩ.
NOTICE! For motors with an integrated capacitor,
short-circuit the windings prior to checking!

6.5.2.2 Test the resistor of the temperature sensor

Measure the resistor of the temperature sensors with an
ohmmeter. The bimetallic strips must have a measured
value of 0 Ohm (passage).
6.5.2.3 Testing the resistor of the external electrode for seal-
ing chamber control
Measure the resistor of the electrode with an ohmmeter.
The measured value must approach "infinity". For values
≤ 30 kOhm, if there is water in the oil – change the oil!
6.5.3 Connection of the single-phase current motor
PE
Fig. 7: Connection diagram single-phase current motor
Wire colour Terminal
Brown (bn) L
en
N L
C r
M 1~
45