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Installation and electrical connection
24
WILO SE 2021-05
Residual-current device (RCD)
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Install a residual-current device (RCD) in accordance with the regulations of the local
energy supply company.
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If people can come into contact with the device and conductive fluids, install a re-
sidual-current device (RCD).
6.5.2
Maintenance tasks
Carry out the following maintenance tasks prior to installation:
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Check the insulation resistance of the motor winding.
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Test the resistance of the temperature sensor.
There are several reasons if the measured values differ from the specifications:
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Humidity in the motor.
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Humidity in the connection cable.
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Monitoring device faulty.
Contact customer service in the event of a fault.
6.5.2.1
Checking the insulation resistance
of the motor winding
Use an insulation tester to measure the insulation resistance (measuring
voltage = 1000 V). Observe the following values:
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At the time of initial commissioning: Insulation resistance may not be less than
20 MΩ.
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For further measurements: Value must be greater than 2 MΩ.
6.5.2.2
Test the resistor of the temper-
ature sensor
Measure the resistor of the temperature sensors with an ohmmeter. The following
measured values must be complied with:
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Bimetallic strip
: Measured value = 0 Ohm (passage).
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PTC sensor
(PTC thermistor): Measured value depends on the number of sensors in-
stalled. At PTC sensor has a cold resistance of between 20 and 100 Ohm.
–
With
three
sensors in series, the measured value is between 60 und 300 Ohm.
–
With
four
sensors in series, the measured value is between 80 und 400 Ohm.
6.5.2.3
Check the resistance of the ex-
ternal electrode for pre-chamber
monitoring
Measure the resistor of the electrode with an ohmmeter. The measured value must ap-
proach “infinity”. For values ≤ 30 kOhm, if there is water in the oil – change the oil!
6.5.3
Three-phase motor connection
The three-phase current version is supplied with bare cable ends. Connection to the
mains is made by connecting the connection cables in the switchgear. Refer to the at-
tached connection 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 starting
U, V, W
Mains connection
PE (gn-ye)
Earth
Wiring diagram of the power connections for star-delta starting
U1, V1, W2
Mains connection (start of winding)
U2, V2, W2
Mains connection (end of winding)
PE (gn-ye)
Earth
6.5.4
Monitoring equipment connection
Refer to the enclosed connection diagram for details regarding the connection and in-
stallation 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.
