Wilo Rexa CUT GI Instrucciones De Instalación Y Funcionamiento página 22

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6.5.2 Maintenance work
6.5.2.1 Checking insulation resistance of
the motor winding
6.5.2.2 Checking resistor in the tempera-
ture sensor
6.5.2.3 Testing the resistor of the exter-
nal electrode for sealing chamber
control
6.5.3 Connection of the single-phase
AC motor
PE N
C r
M 1~
Fig. 7: Connection diagram of the single-phase
AC motor
22
Installation and electrical connection
Residual-current device (RCD)
Adhere to the regulations of the local energy supply company! We recommend using a
residual-current device (RCD).
If persons come into contact with the product and conductive liquids, secure connection
with a residual-current device (RCD).
Before installation carry out the following maintenance work:
▪ Check insulation resistance of the motor winding.
▪ Check resistor in the temperature sensor.
▪ Test the resistor 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.
In case of failure contact customer service.
Measure insulation resistance with an insulation tester (measuring voltage = 1000 V). Ad-
here to the following values:
▪ On initial commissioning: insulation resistance may not be less than 20 MΩ.
▪ For further measurements: value must be larger than 2 MΩ.
NOTICE! For motors with an integrated capacitor, short circuit the windings before
checking!
Check the resistor in the temperature sensor with an ohmmeter. The bimetallic strip must
have a measured value of 0 ohm (conductivity).
Measure the resistor of the electrode with an ohmmeter. The measured value must ap-
proach "infinity". For values ≤ 30 kOhm, there is water in the oil – change the oil!
The single-phase current version is equipped with bare cable ends. Connection to the mains
is established by connecting the power supply cable in the switchgear. Electrical connec-
tion must always be carried out by a qualified electrician!
NOTICE! The individual wires are designated according to the connection diagram. Do
not cut the wires! There is no additional assignment between the wiring diagram and
connection diagram.
L
Wire color
Black (bk)
White (wh)
Red (rd)
Green (gn)
Designation
U1/Z1
U2
Z2
Terminal
L
N
Connection of operating ca-
pacitor (C )
R
Ground
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