Mounting; Electrical Connection; Electrical Protection; Mains And Motor Connection - Grundfos CUE Series Installation And Operating Instructions Manual

5.4 Mounting

The user is responsible for mounting the CUE
Caution
securely on a firm surface.
1. Mark and drill holes. See the dimensions in section 16.2.
2. Fit the screws, but leave loose. Mount the CUE, and tighten
the four screws.
Fig. 4 Drilling of holes

6. Electrical connection

Warning
The owner or installer is responsible for ensuring
correct grounding and protection according to
national and local standards.
Warning
Before making any work on the CUE, the mains
supply and other voltage inputs must be
switched off for at least as long as stated in
section 3. Safety and warnings.
ELCB
Fig. 5 Example of three-phase mains connection of the CUE
with mains switch, back-up fuses and additional
protection

6.1 Electrical protection

6.1.1 Protection against electric shock, indirect contact
Warning
The CUE must be grounded correctly and
protected against indirect contact according to
national regulations.
The leakage current to ground exceeds 3.5 mA,
Caution
and a reinforced ground connection is required.
Protective conductors must always have a yellow/green (PE) or
yellow/green/blue (PEN) color marking.
8
b
a a
b
Instructions according to EN IEC 61800-5-1:
• The CUE must be stationary, installed permanently and
connected permanently to the mains supply.
• The ground connection must be carried out with duplicate
protective conductors or with a single reinforced protective
conductor with a gauge size of minimum 8 AWG.
6.1.2 Protection against short-circuit, fuses
The CUE and the supply system must be protected against short-
circuit.
Grundfos demands that the back-up fuses mentioned in section
16.6 are used for protection against short-circuit.
The CUE offers complete short-circuit protection in case of
a short-circuit on the motor output.
6.1.3 Additional protection
Caution The leakage current to ground exceeds 3.5 mA.
If the CUE is connected to an electrical installation where an
earth leakage circuit breaker (ELCB) is used as additional
protection, the circuit breaker must be of a type marked with the
following symbols:
The circuit breaker is type B.
The total leakage current of all the electrical equipment in the
installation must be taken into account.
The leakage current of the CUE in normal operation can be seen
in section 16.7.1 Mains supply (L1, L2, L3).
During start and in asymmetrical supply systems, the leakage
current can be higher than normal and may cause the ELCB to
trip.
6.1.4 Motor protection
The motor requires no external motor protection. The CUE
protects the motor against thermal overloading and blocking.
6.1.5 Protection against overcurrent
The CUE has an internal overcurrent protection for overload
protection on the motor output.
6.1.6 Protection against supply voltage transients
The CUE is protected against supply voltage transients according
to EN 61800-3, second environment.

6.2 Mains and motor connection

The supply voltage and frequency are marked on the CUE
nameplate. Make sure that the CUE is suitable for the power
supply of the installation site.
The maximum output voltage of the CUE is equal
to the input voltage.
Note
Example: If the supply voltage is 208 V, choose
a 208 V rated motor.
6.2.1 Mains switch
A mains switch can be installed before the CUE according to local
regulations. See fig. 5.
ELCB