Connecting The Signal Terminals - Grundfos CU331SP Installation And Operating Instructions Manual

The cable screen must be exposed and in
Note
Note
physical contact with the mounting plate and
clamp

7.3 Connecting the signal terminals

As a precaution, signal cables must be separated
Caution
from other groups by reinforced insulation in
their entire lengths.
If no external On/Off switch is connected, short-
Note
Note
circuit terminals 18 and 20 using a short wire.
Connect the signal cables according to the guidelines for good
practice to ensure EMC-correct installation. See
installation.
• Use screened signal cables with a conductor cross-section of
2
min. AWG 20 (0.5 mm ) and max. AWG 16 (1.5 mm
• Use a 3-conductor screened bus cable in new systems.
7.3.1 Minimum connection, signal terminal
Operation is only possible when the terminals 18 and 20 are
connected, for instance by means of an external On/Off switch or
a short wire.
Jumper wire
Fig. 8 Required minimum connection, signal terminal
6
7.5 EMC-correct
2
).
Jumper wire
Fig. 9
Fig. 10 Sensor wiring diagram
7.3.2 Setting the analog input 54
The contact A54 is positioned behind the control panel and is
used for setting the signal type of the analog input.
The factory setting of the inputs is voltage signal "U". This setting
must be changed to "I" prior to starting the CU331SP. Be sure the
power supply is switched off.
Note
Note
Remove the control panel to set the contact. See fig. 11.
Fig. 11 Setting contact A54 to current signal "I"
0/4-20 mA
Wiring diagram for CU331SP
Switch off the power supply before setting the
A54.
A54
U I
Terminals
Switch position
must be
changed to "I"
prior to startup