9.3.2 Three-phase supply voltage
Three-phase motors are available for the voltages
below:
• 3 x 380-500 V - 10 %/+ 10 %, 50/60 Hz, PE
• 3 x 200-240 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 Supply
voltage.
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.
Only the following motors can be supplied through an
IT network:
• Motors with speed of 1450-2000/2200 rpm and up
to 1.5 kW
• Motors with speed of 2900-4000 rpm or
4000-5900 rpm and up to 2.2 kW.
Corner earthing is not allowed for supply
voltages above 3 x 240 V and 3 x 480 V,
50/60 Hz.
TM053942
Example of a mains-connected motor with mains
switch, backup fuses and additional protection
Pos. Description
1 RCD, type B
TM053495
Mains connection, three-phase motors
Related information
32.1 Supply voltage
9.4 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
the sections on leakage current and 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.
20
English (GB)
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