Installation and electrical connection
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Installation and operating instructions Wilo-Rexa CUT GE
23
With bimetallic strip
Connect the bimetallic strips in the switchgear itself or via an evaluation relay.
Connection values: max. 250 V(AC), 2.5 A, cos φ = 1
Wiring diagram for bimetallic strip
Temperature limiter
20
Bimetallic strip connection
21
Temperature control
21
High temperature connection
20
Centre terminal
22
Low temperature connection
With PTC sensor
Connect the PTC sensor via an evaluation relay. Relay “CM-MSS” is recommended for
this. The threshold is preset.
PTC sensor wiring diagram
Temperature limiter
10
PTC sensor connection
11
Temperature control
11
High temperature connection
10
Centre terminal
12
Low temperature connection
Triggering status with temperature control and limiting
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 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 limit is reached,
the motor must deactivate with manual reactivation.
Note the additional information in the chapter on potentially explosive areas found
in the appendix!
6.5.5.3
Sealing chamber monitoring (ex-
ternal electrode)
Connect the external electrode via an evaluation relay. Relay “NIV 101/A” is recommen-
ded for this. The threshold is 30 kOhm.
When the threshold is reached, a warning must be given or the unit must be
switched off.
CAUTION
Connection of the sealing chamber control
If on reaching the threshold, there is only a warning, the pump could be irreparably
damaged by the water ingress. Deactivation of the pump is always recommended!
6.5.6
Motor protection adjustment
Motor protection must be set depending on the selected activation type.
6.5.6.1
Direct activation
At full load, set the motor protection switch to the rated current (see rating plate). At
partial load, it is recommended to set the motor protection switch 5 % above the cur-
rent measured at the duty point.
6.5.6.2
Star-delta activation
The motor protection setting depends on the installation:
▪ Motor protection installed in the motor line: Set the motor protection to 0.58 x the
rated current.
