Grundfos CU 301 Manuel D'instructions page 27

Fig. 20 Electrical connection of the CU 301
Legend
Pos. Description
Standard pressure sensor
1
+24 VDC, brown lead, terminal 5
Standard pressure sensor
2
Input signal, black lead, terminal 6
Standard pressure sensor
3
Braid, terminal 7
4 Standard pressure sensor
5 Connections for operating relay
8.1.1 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 con-
nected to any of the two leads. Torque: 15 lbf-in.
Connect the PE terminal to the green/yellow earth
lead. Torque: 9.0 - 15.3 lbf-in. Each PE terminal must
be connected to an earth lead of its own.
Maximum wire size of the leads to be connected is
10 AWG.
Circuit breaker: Maximum 16 A.
Note: The leads of the mains supply must not be
connected to terminals 3 and 4 (PUMP).
8.1.2 Pump supply
PUMP, terminals 3, 4 and PE
Connect terminals 3 and 4 to the phase and neutral
leads of the pump. Each terminal can be connected
to any of the two leads. Torque: 15 lbf-in.
Connect the PE terminal to the green/yellow earth
lead. Torque: 9.0 - 15.3 lbf-in. Each PE terminal must
be connected to an earth lead of its own.
Maximum wire size of the leads to be connected is
10 AWG.
1 2 3 4
POWER PUMP
PE
PE
L N N L
5
3
1
2
4
In situations where multiple CU 301 pump power
cables are run parallel in wiring trays or conduit and
less than 10-12 inches apart, the possibility for
undesired communication between units exists.
When this occurs, intermittent or continuous "No
contact" is typically seen. Other unexpected errors
may also be seen.
Refer to section 5.3.10 Number for further instruc-
tions.
8.1.3 Pressure sensor
SENSOR, terminals 5, 6 and 7
Terminals 5, 6 and 7 (SENSOR) are used for the
pressure sensor.
Sensor signals
The sensor to be connected must provide signals
within one of the following ranges:
• 0-10 V
• 2-10 V
• 0-20 mA
• 4-20 mA - factory default.
Changeover between current and voltage signals is
carried out by means of the R100.
Important!
The total load of terminal 5 (+24 VDC) must not
exceed 100 mA.
RELAY, terminals 8 and 9
Terminals 8 and 9 (RELAY) are used for the connec-
tion of an external signal transmitter (sound or light).
The operating relay is a normally open contact when
the pump is not running, and closes while the pump
is running.
Relay specifications
Maximum load: 230 VAC, 0.5 A.
27