Goodrive800 Pro Series Inverter Unit Hardware Manual
Electrical installation
202202 (V1.0)
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effective and lowest-cost solution for EMC problems.
Three categories of grounding: special pole grounding, common pole grounding and series-wound
grounding. Different control system needs to use special pole grounding, different devices in the same
control system needs to use common pole grounding, and different devices connected by the same power
cables needs to use series-wound grounding.
4.3.1
Power cable
To meet the EMC requirements stipulated in the CE standards, you must use symmetrical shielded cables as
motor cables.
Four-core cables can be used as input cables, but symmetrical shielded cables are recommended.
Compared with four-core cables, symmetrical shielded cables can reduce electromagnetic radiation as well
as the current and loss of the motor cables.
L1
L2
L3
PE
PE
PE
L1
L2
L3
PE
L1
L2
L4
L3
Symmetrical shielded cable,
PEs in symmetrical manner
Symmetrical shielded cable, PE
in separated manner
Asymmetrical four-core
cable
Power cables must meet the following requirements:
The sizes of the input power cables and motor cables must comply with local regulations.
The input power cables and motor cables must be able to carry the corresponding load currents.
The maximum temperature margin of the motor cables in continuous operation cannot be lower than
70°C.
PE grounding conductor conductivity must be as good as possible to reduce the grounding resistance to
achieve better impedance continuity. If the electrical conductivity of the motor cable shield layer does
not meet the requirements, a separate PE conductor must be used.
To effectively restrict the emission and conduction of radio frequency (RF) interference, the conductivity of
the shielded cable must at least be 1/10 of the conductivity of the phase conductor. This requirement can be
well met by a copper or aluminum shield layer. The following figure shows the minimum requirement on
motor cables of a VFD. The cable must consist of a layer of spiral-shaped copper strips. The denser the shield
layer is, the more effectively the electromagnetic interference is restricted.
Figure 4-1 Cable cross section
Insulating layer
Shield layer
Note: Check the insulation conditions of the input power cable of a VFD according to the local
regulations before connecting it.