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English (US)
9.2.2 Three-phase supply voltage
• 3 x 440-480 V - 10 %/+ 10 %, 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.
For maximum backup fuse, see section 27.1 Supply voltage.
Fig. 18 Example of a power supply-connected motor with
power supply switch, backup fuses and additional
protection
Fig. 19 Power supply connection, three-phase motors
9.3 Additional protection
9.3.1 Single-phase motors
If the motor is connected to an electric installation where an earth
leakage circuit breaker (ELCB) or ground fault circuit
interrupter (GFCI) is used as additional protection, this circuit
breaker or interrupter must be marked with the following symbol:
The leakage current of the motor can be found in section
26.2 Leakage current.
9.3.2 Three-phase motors
If the motor is connected to an electric installation where an earth
leakage circuit breaker (ELCB) or ground fault circuit interrupter
(GFCI) is used as additional protection, this circuit breaker or
interrupter must be of the following type:
• It must be suitable for handling leakage currents and cutting-in
with short pulse-shaped leakage.
• It must trip out when alternating fault currents and fault
currents with DC content, i.e. pulsating DC and smooth DC
fault currents, occur.
For these motors an earth leakage circuit breaker or ground fault
circuit interrupter, type B, must be used.
This circuit breaker or interrupter must be marked with the
following symbols:
You find the leakage current of the motor in section 27.2 Leakage
current.
Protection against phase unbalance
The motor 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.
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.
Corner grounding is not allowed for supply
voltages above 3 x 480 V, 60 Hz.
TM05 3942 1812TM05 3495 1512
When an earth leakage circuit breaker or ground
fault circuit interrupter is selected, the total
leakage current of all the electrical equipment in
the installation must be taken into account.
When you select an earth leakage circuit breaker
or ground fault circuit interrupter, take into
account the total leakage current of all the
electrical equipment in the installation.
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