Electrical Connection; Power Supply; Pump Supply - Grundfos CU 301 Mode D'emploi

3.2 Electrical connection

The on/off button on the CU 301 must not be used
as a safety switch when installing and servicing
the pump. Mains disconnect must be provided by
the installer.
Raintight or wet location hubs that comply with the
requirements in the standard for Fittings for
Conduit and Outlet Boxes, UL514B, must be
used. Suitable devices for CU 301 are rated with
enclosure type 3, 3R, 3S, 4, 4X, 6 or 6P.
The supply voltage and frequency are marked on
the nameplate. Ensure that CU 301 is suitable for
the power supply on which it will be used.
If CU 301 is connected to a power supply where a
Ground Fault Circuit Interrupter (GFCI) is used as
an additional protection, this device must trip
when ground fault currents with DC content
(pulsating DC) occur.
For recommended fuse sizes and maximum
leakage current, see section
CU 301 has two terminal blocks:
• Screw terminals 1 to 4.
• Spring terminals 5 to 9.
Furthermore, CU 301 is equipped with two screw
terminals for the ground conductors (PE). Always
use copper conductors approved for 60/75 °C
(140/167 °F).
The on/off button on CU 301 must not be used as
a safety switch when installing and servicing the
pump.
POWER
PUMP
1
2 3 4
PE
PE
L N N L
Electrical connection of CU 301
6
9. Technical data.
Related information
9. Technical data

3.2.1 Power supply

POWER, terminals 1, 2 and PE
Connect terminals 1 and 2 to the phase (L1) and
neutral(L2) conductors of the power supply. Each
terminal can be connected to any of the two
conductors. Torque: 15 lbf-in.
Connect the PE (ground) terminal to the green
and yellow ground conductor. Torque: 9.0 - 15.3
lbf-in. Each PE (ground) terminal must be
connected to a ground conductor of its own.
Maximum wire size of the conductors to be
connected is 10 AWG.
Circuit breaker: maximum 16 A.
The conductors of the power supply
must not be connected to terminals 3
and 4 (PUMP).

3.2.2 Pump supply

PUMP, terminals 3, 4 and PE
Connect terminals 3 and 4 to the phase (L1) and
neutral (L2) conductors of the pump. Each
terminal can be connected to any of the two
conductors. Torque: 15 lbf-in.
Connect the PE (ground) terminal to the green
and yellow ground conductor. Torque: 9.0 - 15.3
lbf-in. Each PE (ground) terminal must be
connected to a ground conductor of its own.
Maximum wire size of the conductors to be
connected is 10 AWG.
In situations where multiple CU 301 pump power
cables are run in parallel in wiring trays or
conduits and less than 10-12 inches (254-305
mm) apart, the possibility of undesired
communication between units exists.
When this occurs, the indicator light for service
alarm comes on, and 'No contact to pump' is
logged in the alarms and warnings. This can be
viewed using Grundfos GO Remote. See section
Number.
Pressure sensor
DANGER
Electric shock
Death or serious personal injury
‐
The total load of terminal 5, +24
VDC, must not exceed 100 mA.
SENSOR, terminals 5, 6 and 7:
Terminals 5, 6 and 7 (SENSOR) are used for the
pressure sensor.