Checking Resistor In The Temperature Sensor; Connection Of The Three-Phase Current Motor; Connection Of The Monitoring Devices - Wilo HC 20.1+EMU FA Instrucciones De Instalación Y Funcionamiento

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 HC 20.1 + EMU FA, Rexa SUPRA, Rexa SOLID
Installation and electrical connection
Measure the resistor of the temperature sensors with an ohmmeter. The following measured
values must be complied with:
▪ PTC sensor (PTC thermistor): Measured value depends on the number of sensors installed. A
PTC sensor has a cold resistance range of 20 to 100 ohms.
– With three sensors in series, the measured value range is from 60 to 300 ohms.
– With four sensors in series, the measured value range is from 80 to 400 ohms.
▪ 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.
DANGER
Risk of explosion due to incorrect connection!
If the monitoring devices are not connected correctly, there is a risk of fatal injury due to
explosion in potentially explosive areas! Connection must always be carried out by a
qualified electrician. If used in potentially explosive areas:
• Connect the thermal motor monitoring via an evaluation relay!
• Deactivation by the temperature limiter must be conducted with an reactivation
lock! It must only be possible to restart the unit when the unlock key has been actu-
ated by hand!
• Connect the external electrode (e.g. sealing chamber control) via an evaluation relay
with an intrinsically safe circuit!
• Note the additional information in the chapter on potentially explosive areas found
in the appendix of these installation and operating instructions!
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