Appendix
en
Installation and operating instructions Wilo-Rexa PRO
43
The
P 13 motor
is equipped with a temperature limiter (1-circuit temperature monitor-
ing). As an option, the motor can be fitted with a temperature controller and limiter (2-
circuit temperature monitoring).
The
P 17 motor
is equipped with a temperature controller and limiter (2-circuit tem-
perature monitoring).
Depending on the version of the thermal motor monitoring, the following triggering
status must occur when the threshold value is reached:
▪ Temperature limiting (1 temperature circuit):
When the threshold is reached, deactivation
with reactivation lock
must take place!
▪ Temperature control (2 temperature circuits):
When the threshold for the low temperature is reached, the motor can deactivate with
automatic 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 reactiva-
tion, 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.
13.2.4.3 Sealing chamber monitoring (ex-
ternal electrode)
▪ 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!
13.2.4.4 Frequency converter operation
▪ Type of converter: Pulse-width modulation
▪ Continuous duty: 30 Hz up to rated frequency (50 Hz or 60 Hz). Comply with the min-
imum flow velocity!
▪ Min. switching frequency: 4 kHz
▪ Max. overvoltages on the terminal board: 3000 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 con-
verter, 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, the temperature class T3 applies.
13.2.5
Commissioning
DANGER
Risk of explosion when using non Ex-rated pumps!
Pumps without Ex rating may not be used in potentially explosive areas! There is a
risk of fatal injury due to explosion! Only use pumps which have the appropriate Ex
labelling on the rating plate within potentially explosive areas.
DANGER
Risk of explosion due to flying sparks in the hydraulics!
During operation the hydraulics must be flooded (completely filled with the fluid). If
the volume flow is interrupted or the hydraulics emerges, air cushions can form in
the hydraulics. If this happens, there is a risk of explosion, e.g. flying sparks due to
static charge! Dry-running protection must ensure that the pump is deactivated at
the appropriate level.
