Grundfos CU 300 Installation and Operating Instructions - Geotech

7.5 Electrical connection
Never make any connections in the
CU 300 unit unless the electricity supply
The supply voltage and frequency are marked on the
nameplate. Make sure that the CU 300 is suitable for
the electricity supply on which it will be used.
has been switched off. The CU 300 must
be connected in accordance with the rules
and standards in force for the application
in question.
Fig. 31
1 2
3 4
K1
POWER
PE
PUMP
5 6 7
NC
COM
NO
8 9 10
NC
COM
NO
111213 141516
171819
+24VDC
IN
GND
+24VDC
IN
GND
+24VDC
IN
GND
B
GND
A RI
DTR
RXD
GND
TXD
PE
ALARM
RELAY
AUX
RELAY
DIG
IN
SENSOR SENSOR
1 2
RS
485
RS
232
H
L N
N
L
SENSOR IN
DIG IN
GND
+24 VDC
4 3 21
SPP 1
TM01 3091 3398
Legend:
Pos.
Description
K1
Internal alarm signal relay
Relay data: 250 VAC, 8 A, AC1
H Alarm signal transmitter (optional)
SPP 1 External Grundfos potentiometer, SPP 1
7.5.1 Mains supply
POWER, terminals 1, 2 and PE:
Connect terminals 1 and 2 to the phase and neutral
leads of the mains supply. Each terminal can be connected
to any of the two leads.
Connect the PE terminal to the green/yellow earth
lead. Each PE terminal must be connected to an
earth lead of its own.
Maximum cross-section of the leads to be connected
is 6 mm².
Back-up fuse: Maximum 16 A.
Note: The leads of the mains supply must not be
connected to terminals 3 and 4 (PUMP).
28