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 three-phase
current motor
6.5.4
Connection of the monitoring de-
vices
Installation and operating instructions Wilo Motor T 12 ... 72 + EMU FA, Rexa SUPRA, Rexa SOLID
Installation and electrical connection
▪ 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.
Check the resistor in the temperature sensor with an ohmmeter. The following measured
values must be complied with:
▪ Bimetallic strip: Measured value = 0 Ohm (passage).
▪ PTC sensor (positive temperature coefficient thermistor): Measured value depends on the
number of sensors installed. A PTC sensor has a cold resistance of between 20 and
100 Ohm.
– With three sensors in series, the measured value is between 60 and 300 Ohm.
– With four sensors in series, the measured value is between 80 and 400 Ohm.
▪ Pt100 sensor: Pt100 sensors have a resistance value of 100 ohms at 0 °C (32 °F). Between
0 °C (32 °F) and 100 °C (212 °F), the resistance increases by 0.385 ohms per 1 °C (1.8 °F) in-
crease.
At an ambient temperature of 20 °C (68 °F), the resistance is 107.7 ohms.
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 three-phase version is supplied with bare cable ends. Connection to the mains is estab-
lished by connecting the power supply cables in the switchgear. Refer to the attached con-
nection diagram for more precise details regarding the connection. Electrical connection
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.
Wiring diagram of the power connections for direct activation
Mains connection
U, V, W
PE (green-yel-
Ground
low)
Wiring diagram of the power connections for star-delta starting
Mains connection (start of winding)
U1, V1, W2
Mains connection (end of winding)
U2, V2, W2
PE (green-yel-
Ground
low)
Refer to the enclosed connection diagram for details regarding the connection and installa-
tion of the monitoring devices. Electrical connection 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.
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