Grundfos CU331SP, Installation And Operating Instructions Manual

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Eng
lish (US)
6
7.3 Connecting the signal terminals
Connect the signal cables according to the guidelines for good
practice to ensure EMC-correct installation. See
7.5 EMC-correct
installation .
• Use screened signal cables with a conductor cross-section of
min. AWG 20 (0.5 mm
2
) and max. AWG 16 (1.5 mm
2
).
• 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.
Fig. 8 Required minimum connection, signal terminal
Fig. 9 Wiring diagram for CU331SP
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.
Remove the control panel to set the contact. See fig. 11 .
Fig. 11 Setting contact A54 to current signal "I"
Note
Note
The cable screen must be exposed and in
physical contact with the mounting plate and
clamp
Caution
As a precaution, signal cables must be separated
from other groups by reinforced insulation in
their entire lengths.
Note Note
If no external On/Off switch is connected, short-
circuit terminals 18 and 20 using a short wire.
TM
03 905
7 320
7
S
tart
/stop
GND
Jumper wire
TM
05
5
802
39
13
TM
05 67
76 51
12
Note
Note
Switch off the power supply before setting the
A54.
T
M
05
58
03
39
12
0/4-20 mA
Terminals
Sensor 1
GND
GND
+24 V out Start/stop
R
S
-485 GND
Y
RS-48
5
B
RS-
485 A
Switch position
must be
changed to "I"
prior to startup
Jumper wire
U I
A54