Power Wiring
ANCA Motion
DS619-0-00-0019 - Rev 0
39
6
induce parasitic common mode currents (I
LEAK
) in the stray capacitance of the motor and cable system. See
Figure 6-4.
The common mode currents return to the drive inverter by lowest available impedance paths which
must be carefully managed to prevent interference voltages being generated to other equipment connected to the
same earth system. Internal common mode capacitors of the drive provide one return path (I
DC
) to the drive, and
the EMC filter provides another return path via the drive mains input.
A correctly sized EMC filter limits the high-frequency harmonic effects on the supply systems of the drive by
reducing the conducted emissions in the frequency range between 150 kHz and 30 MHz. The EMC filter ensures
that disturbances produced by the drive are mainly kept inside the drive system itself and that only a small
percentage (within the permissible tolerance range) can spread into the supply system.
Figure 6-4
shows a
variable-speed drive system which comprises a cabinet-mounted AMD2000 drive which is supplying a motor via
a shielded motor cable. Common mode currents can also return to the supply transformer star point where the
PE is bonded to supply phase lines. Thus EMC currents may affect other equipment connected to the same Point
of Common Coupling (PCC).
Line Reactor
IGBT Inverter
Line Filter
AMD2000
Motor Cable
I
leak
PE terminal and metal gear tray ground
PE
I
PCC
Converter Cabinet
LF
I
DC
I
Heatsink
Figure 6-4 Common Mode Noise Current Paths in a Drive System
6.5.11
EMC Filter Specifications
To ensure the installation meets the emission standard for power drive system IEC61800-3 the correct EMC filter
on the mains supply must be used.
Recommended EMC filters for mains power and control supply
AMD2000, 3A & 9A 3 phase supply
Schaffner 3-phase 10A EMC Filter
FN3270H-10-44
AMD2000, 1 phase control supply
Schaffner 1-phase 1A EMC Filter
FN 343-1-05
Meeting the requirements of IEC61800-3 depends on the drive installation configuration and all of the
guidelines below must be followed. If no EMC filter is installed then the drive may cause interference to the drive
control system and to other nearby electronic equipment. Note that interference can be from both conducted
emission and radiated emission. An EMC filter also improves a system’s resistance to interference from external
sources at the point of common coupling