Mains; Aggressive Environment; Reduced Performance Under Certain Conditions; Mechanical Installation - Grundfos CUE Series Installation And Operating Instructions Manual

The general safety necessitates special considerations as to
these aspects:
• fuses and switches for overcurrent and short-circuit protection
• selection of cables (mains current, motor, load distribution and
relay)
• net configuration (IT, TN, earthing)
• safety on connecting inputs and outputs (PELV).
4.1 IT mains
Do not connect 380-500 V CUE frequency converters
to mains supplies with a voltage between phase and
protective earth of more than 440 V.
In connection with IT mains and earthed delta mains, the mains
voltage may exceed 440 V between phase and protective earth.

4.2 Aggressive environment

CUE must not be installed in an environment where
the air contains liquids, particles or gases which may
affect and damage the electronic components.
CUE contains a large number of mechanical and electronic
components. They are all vulnerable to environmental impact.

4.3 Reduced performance under certain conditions

CUE reduces its performance under these conditions:
• low air pressure (at high altitude)
• long motor cables.
The required measures are described in the next two sections.
4.3.1 Reduction at low air pressure
At altitudes above 2000 m (6600 ft), the PELV
requirements cannot be met.
PELV = Protective Extra Low Voltage.
At low air pressure, the cooling capacity of air is reduced, and
CUE automatically reduces the performance to prevent overload.
It may be necessary to select a CUE unit with a higher
performance.
4.3.2 Reduction in connection with long motor cables
The maximum cable length is 300 m (1000 ft) for unscreened and
150 m (500 ft) for screened cables. In case of longer cables,
contact Grundfos.
CUE is designed for a motor cable with a maximum cross-section
as stated in section 12.3.4 Non-UL fuses and conductor cross-
section to mains and motor, for installations outside North
America and 12.3.5 UL fuses and conductor cross-section to
mains and motor, for installations in North

5. Mechanical installation

The individual CUE cabinet sizes are characterised by their
enclosures. The table in section
relationship between enclosure class and enclosure type.

5.1 Enclosure types

Products with integrated STO function must be installed in an
IP54 cabinet according to IEC 60529 or in an equivalent
environment. In special applications, a higher IP degree may be
necessary.

5.2 Space requirements and air circulation

CUE units can be mounted side by side, but as sufficient air
circulation is required for cooling, these requirements must be
met:
•
•
•
Required free space above and below the CUE cabinet
Enclosure
A2, A3, A4, A5
B1, B2, B3, B4, C1, C3
C2, C4, D1h, D2h

5.3 Mounting

1. Mark and drill holes. See section
2. Fit the screws at the bottom, but leave loose. Mount CUE, and
America.
12.1 Enclosure
Sufficient free space above and below the CUE cabinet. See
the table below.
Ambient temperature up to 50 °C (122 °F)
Hang the CUE cabinet directly on the wall, or fit it with a back
plate. See fig. 4.
Fig. 4 CUE hung directly on the wall or fitted with a back
plate
The user is responsible for mounting CUE securely
on a firm surface.
B1-B4 and C1-C4..
tighten the four screws.
Fig. 5 Drilling of holes in the wall
shows the
Space [mm (in)]
100 (3.9)
200 (7.9)
225 (8.9)
12.5.1 Enclosures A2-A5,
b
a a
b
5