Grundfos MGE Series - Additional protection

English (GB)
10
7.3.2 Three-phase supply voltage
• 3 x 380-500 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
earth 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, ensure that the
terminal block for L1, L2 and L3 is pressed home in
its socket when the supply cable has been
connected.
For maximum backup fuse, see section 23.1 Supply
voltage.
Fig. 8 Example of a mains-connected
three-phase motor with mains switch,
backup fuses and additional protection
Fig. 9 Mains connection, three-phase motors
7.4 Additional protection
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
section 23.2 Leakage current (AC).
This product can cause a direct current in the
protective earth 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.
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 earthing is not allowed for supply
voltages above 3 x 480 V, 50/60 Hz.
MGE 71, 80, 90, 100, 112, 132, 160
TM05 3942 1812
MGE 71, 80, 90, 100, 112, 132, 160
TM05 3495 1512
L1
L2
L3
L2
L1
L3
PE
RCD,
type B
DANGER
Electric shock
- Death or serious personal injury
- Only use residual-current circuit
breakers (ELCB, GFCI, RCD) of type B.
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.