Grundfos LCSE Installation And Operating Instructions Manual page 8

Three-phase supply voltage
• 3 x 440-480 V - 10 %/+ 10 %, 50/60 Hz, PE.
Check that the supply voltage and frequency correspond to the
values stated on the nameplate.
The wires in the motor terminal box must be as short as possible.
Excepted from this is the separated ground conductor which must
be so long that it is the last one to be disconnected in case the
cable is inadvertently pulled out of the cable entry.
In order to avoid loose connections, make sure that you have
pressed home the terminal block for L1, L2 and L3 in its socket
when you connect the supply cable.
For maximum backup fuse, see section
If you want to supply the motor through an IT
network, make sure that you have a suitable motor
variant. If you are in doubt, contact Grundfos.
Corner grounding is not allowed for supply voltages
above 3 x 480 V, 50/60 Hz.
RCD, type B
L1
L2
L3
PE
Fig. 6 Example of a power supply-connected motor with
power supply switch, backup fuses and additional
protection
Fig. 7 Power supply connection, three-phase motors
8
10.4.1 Supply voltage.
L1
L2
L3
4.2.4 Additional protection
DANGER
Electric shock
Death or serious personal injury
- Only use residual-current circuit breakers (ELCB,
GFCI, RCD) of type B.
The residual-current circuit breaker must be marked with the
following symbol:
The total leakage current of all the electrical equipment in the
installation must be taken into account. You find the leakage
current of the motor in sections
10.4.2 Leakage current (AC).
This product can cause a direct current in the protective ground
conductor.
Overvoltage and undervoltage protection
Overvoltage and undervoltage may occur in case of unstable
power supply or a faulty installation. The motor is stopped if the
voltage falls outside the permissible voltage range. The motor
restarts automatically when the voltage is again within the
permissible voltage range. Therefore, no additional protection
relay is required.
The motor is protected against transients from the
power supply according to EN 61800-3. In areas with
high lightning intensity, we recommend external
lightning protection.
Overload protection
If the upper load limit is exceeded, the motor automatically
compensates for this by reducing the speed and stops if the
overload condition persists.
The motor remains stopped for a set period. After this period, the
motor automatically attempts to restart. The overload protection
prevents damage to the motor. Consequently, no additional motor
protection is required.
Overtemperature protection
The electronic unit has a built-in temperature sensor as an
additional protection. When the temperature rises above a certain
level, the motor automatically compensates for this by reducing
the speed and stops if the temperature keeps rising. The motor
remains stopped for a set period. After this period, the motor
automatically attempts to restart.
Protection against phase unbalance
Three-phase motors must be connected to a power supply with a
quality corresponding to IEC 60146-1-1, class C, to ensure
correct motor operation at phase unbalance. This also ensures
long life of the components.
and
10.3.2 Leakage current