Location; Enclosure Class; Terminals; Mechanical Installation - Grundfos CU 351 Montage- Und Betriebsanleitung

Warning

The installation must incorporate a
circuit breaker in order to switch off the
mains supply. It must be close to the
CU 351 and easily accessible for the
operator. It must be marked as circuit
breaker for the CU 351. The circuit
breaker must be according to
IEC 60947-1 and IEC 60947-3.

3.1 Location

The CU 351 is designed for indoor installation.
For outdoor installation the CU 351 must be mounted
in a suitable panel.

3.2 Enclosure class

In order to reduce the external pollution level to
maximum 2, the CU 351 must be installed in a
protecting environment with minimum IPX4
enclosure according to IEC 60529. The cabinet must
be of a flame-retardant material.
The CU 351 is IP54 when mounted in the front of an
IPX4 enclosure.
For USA and Canada only: The CU 351 is type 3R
and 12 when mounted in the front of a cabinet with
type rating 1, 2, 3, 3R, 5, 12, 12K or 13.

3.3 Terminals

All terminals are suitable for conductors of 0.5 to
2
2.5 mm or AWG 20-13.

4. Mechanical installation

The CU 351 can be mounted in the front of a control
panel or a separate cabinet.
Min. 1.5 mm
Max. 3 mm
Fig. 4 Mounting in panel front (standard)
Fasten the CU 351 with the four screws, M5 x 10
supplied with the unit (see pos. 1).
Maximum torque: 1.4 Nm.
Dimensions of the CU 351, see 14. Dimensions.
In order to achieve enclosure class
Note
IP54, the CU 351 must be mounted in
a panel or cabinet.
Fig. 5 Earth connection
Connect the earth terminal (cable clamp) on the
CU 351 to the mounting frame (pos. 2, fig. 4) as
shown in fig. 5.

5. EMC-correct installation

The CU 351 is normally mounted in a panel which
also contains an IO 351 module, frequency
converters, contactors and other power equipment.
In order to ensure a faultless function, it is very
important to install the electronic modules in an
EMC-correct way:
• Ensure a sufficient earth connection between the
CU 351 and the frame, see fig. 5.
• Use screened cables for GENIbus. Connect the
screen to the cable clamp of the CU 351 forward
of the terminals B, Y and A (pos. 3) and A1, Y1
and B1 (pos. 2).
Fig. 6 Screen fixed with cable clamp
Any isolating plastic tape between
screen and sheath must be removed
Note
before mounting the cable in the cable
clamp.
• Signal conductors for digital and analog inputs
and outputs should be screened, i.e. run the
screen all the way to the CU 351 and connect it
to frame with for instance a cable clamp.
Alternatively, the signal conductors in the panel
may be unscreened if the panel is divided into a
power and a low-voltage area. Unscreened signal
conductors must not run in the power area, but
exclusively in ducts in the low-voltage area.
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