Installation and electrical connection
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Installation and operating instructions Wilo Motor T 12 ... 72 + EMU FA, Rexa SUPRA, Rexa SOLID
31
ƒ
PTC sensor
(PTC thermistor): Measured value depends on the number of sensors in-
stalled. 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.
ƒ
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) increase.
At an ambient temperature of 20 °C (68 °F), the resistance is 107.7 ohms.
6.5.2.3
Testing the resistor of the ex-
ternal electrode for sealing cham-
ber control
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 established by connecting the power supply cables in the switchgear. Refer to
the attached 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 activation
U, V, W
Mains connection
PE (green-yel-
low)
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 (green-yel-
low)
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.
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 reactivation
lock! It must only be possible to restart the unit when the unlock key has been
actuated 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!
Summary of Contents for EMU FA
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