Wilo Rexa PRO Serie Instrucciones De Instalación Y Funcionamiento página 47

13.2.4.2 Monitoring the motor winding
13.2.4.3 Sealing chamber monitoring (ex-
ternal electrode)
13.2.4.4 Operation on frequency converter ▪ Type of converter: Pulse-width modulation
Installation and operating instructions Wilo-Rexa PRO
Appendix
DANGER
Risk of explosion due to overheating of the motor!
If the temperature limiter is connected incorrectly, there is risk of explosion due to over-
heating of the motor! Always connect the temperature limiter to a manual reactivation
lock. This means that a "release button" must be manually activated!
The P 13 motor is equipped with a temperature limiter (single-circuit temperature monitor-
ing). As an option, the motor can be fitted with a temperature controller and limiter (2-cir-
cuit temperature monitoring).
The P 17 motor is equipped with a temperature controller and limiter (2-circuit temperature
monitoring).
Depending on the version of the thermal motor monitoring, the following triggering status
must occur when the threshold value is reached:
▪ Temperature limiter (1 temperature circuit):
When the threshold is reached, deactivation with reactivation lock must take place!
▪ Temperature controller and limiter (2 temperature circuits):
When the threshold for the low temperature is reached, the motor can deactivate with au-
tomatic reactivation. When the threshold for the high temperature is reached, the motor
must deactivate with reactivation lock!
CAUTION! Motor damage due to overheating! In the event of automatic reactivation,
comply with the specifications for the maximum switching frequency and switching
break!
Connection of the thermal motor monitoring
▪ Connect the bimetallic strip via an evaluation relay. Relay "CM-MSS" is recommended for
this. The threshold is preset.
Connection values: max. 250 V(AC), 2.5 A, cos φ = 1
▪ Connect the PTC sensor via an evaluation relay. Relay "CM-MSS" is recommended for this.
The threshold is preset.
▪ Connect the external pencil electrode via an Ex-rated evaluation relay! Relay "XR-4..." is
recommended for this.
The threshold is 30 kOhm.
▪ The connection must be made using an intrinsically safe circuit!
▪ Continuous duty: 30 Hz up to rated frequency (50 Hz or 60 Hz). Comply with the minimum
flow velocity!
▪ Min. switching frequency: 4 kHz
▪ Max. overvoltages on the terminal board: 1350 V
▪ Output current on the frequency converter: max. 1.5 times rated current
▪ Max. overload time: 60 s
▪ Torque applications: quadratic pump curve
Speed/torque curves required are available on request!
▪ Observe additional measures with regard to EMC regulations (choice of frequency converter,
filters, etc.).
▪ Never exceed the rated current or rated speed of the motor.
▪ It must be possible to connect the motor's own temperature monitoring (bimetallic strip or
PTC sensor).
▪ If the temperature class is marked as T4/T3, temperature class T3 applies.
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