References; Safety And Warnings; Warning; Safety Regulations - Grundfos CUE Series Installation And Operating Instructions Manual

2.3 References

Technical documentation for Grundfos CUE:
• The manual contains all information required for putting the
CUE into operation.
• The data booklet contains all technical information about the
construction and applications of the CUE.
• Service instructions contain all required instructions for
dismantling and repairing the variable frequency drive.
Technical documentation is available on www.grundfos.com >
International website > WebCAPS.
If you have any questions, please contact the nearest Grundfos
company or service workshop.

3. Safety and warnings

3.1 Warning

Warning
Any installation, maintenance and inspection
must be carried out by trained personnel.
Warning
Touching the electrical parts may be fatal, even
after the CUE has been switched off.
Before making any work on the CUE, the mains
supply and other input voltages must be
switched off at least for as long as stated below.
Voltage
4 minutes
200-240 V 1 - 5 hp
380-500 V 0.75 - 10 hp
525-600 V 1 - 10 hp
525-690 V
Wait only for shorter time if stated so on the nameplate of the
CUE in question.

3.2 Safety regulations

• The On/Off button of the control panel does not disconnect the
CUE from the power supply and must therefore not be used as
a safety switch.
• The CUE must be grounded correctly and protected against
indirect contact according to national regulations.
• The leakage current to ground exceeds 3.5 mA.
• Enclosure class NEMA 1 must not be installed freely
accessible, but only in a panel.
• Enclosure class NEMA 12 must not be installed outdoors
without additional protection against water and the sun.
• Always observe national and local regulations as to cable
gauge size, short-circuit protection and overcurrent protection.
6
Min. waiting time
15 minutes 20 minutes
7.5 - 60 hp
15 - 125 hp
15 - 125 hp

3.3 Installation requirements

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, grounding)
• safety on connecting inputs and outputs (PELV).
3.3.1 IT mains
Warning
Do not connect 380-500 V CUE variable frequency
drives to mains supplies with a voltage between
phase and ground of more than 440 V.
In connection with IT mains and grounded delta mains, the supply
voltage may exceed 440 V between phase and ground.
3.3.2 Aggressive environment
The CUE should not be installed in an
environment where the air contains liquids,
Caution
particles or gases which may affect and damage
the electronic components.
The CUE contains a large number of mechanical and electronic
components. They are all vulnerable to environmental effects.

3.4 Reduced performance under certain conditions

The CUE will reduce its performance under these conditions:
• low air pressure (at high altitude)
• long motor cables.
The required measures are described in the next two sections.
3.4.1 Reduction at low air pressure
Warning
At altitudes above 6600 ft, PELV cannot be met.
PELV = Protective Extra Low Voltage.
At low air pressure, the cooling capacity of air is reduced, and the
CUE automatically reduces the performance to prevent overload.
It may be necessary to select a CUE with a higher performance.
3.4.2 Reduction in connection with long motor cables
The maximum cable length for the CUE is 1000 ft for unscreened
and 500 ft for screened cables. In case of longer cables, contact
Grundfos.
The CUE is designed for a motor cable with a maximum gauge
size as stated in section 16.6 Fuses and cable gauge size.