Installation and Connection
CFW-11M G2 | 3-25
3
NOTE!
The magnetic field created by the current circulation in these cables may induce currents in nearby
metal parts, heating them, and cause additional electrical losses. Therefore, keep the three cables
(U, V, W) always together.
Shielded Cables:
They are mandatory when it is necessary to comply with the electromagnetic compatibility directive (89/336/
EEC), as defined by EN 61800-3 “Adjustable Speed Electrical Power Drive Systems”. It mainly acts reducing the
electromagnetic radiation disturbance produced by the motor cables in the radio frequency band.
Regarding the installation types and details, follow the recommendations of IEC 60034-25 “Guide For Design
and Performance of Cage Induction Motors Specifically Designed For Converter Supply”; see summary in
. Refer to the standard for further details and occasional changes related to the new revisions.
Keep motor cables away from other cables (signal cables, sensor cables, control cables, etc.), according to
.
The grounding system must be well interconnected among the several installation locations such as the grounding
points of the motor and the inverter. Voltage difference or impedance between the several points may cause the
circulation of parasite currents among the equipments connected to the ground, resulting in electromagnetic
interference problems.
Table 3.10:
Minimum separation distance between motor cables and all other cables
Cable Length
Minimum Separation
Distance
≤ 30 m (100 ft)
≥ 10 cm (3.94 in)
> 30 m (100 ft)
≥ 25 cm (9.84 in)
U
U
U
W
W
W
V
SCu
SCu
PE
PE
PE
AFe
PEs
V
V
Symmetrical shielded cables: three concentric conductors with or without a ground conductor, symmetrically manufactured, with an
external shield of copper or aluminum.
Note:
(1)
SCu = copper or aluminum external shield.
(2)
AFe = galvanized steel or iron.
(3)
PE = ground conductor.
(4)
Cable shielding must be grounded at both ends (inverter and motor). Use 360º connections for low impedance to high frequencies.
(5)
For using the shield as a protective ground, it must have at least 50 % of the power cables conductivity. Otherwise, add an external ground conductor
and use the shield as an EMC protection.
(6)
Shielding conductivity at high frequencies must be at least 10 % of the phase power cable conductivity.
Figure 3.29:
Motor connection cables recommended by IEC 60034-25
3.2.8 Grounding Connections
DANGER!
Do not share the grounding wiring with other equipment that operate with high currents (e.g. high
power motors, soldering machines, etc.).
DANGER!
Ne pas partager le câblage de mise à la terre avec d’autres équipements opérant avec des intensités
élevées (par ex: moteurs haute puissance, postes de soudure, etc.).
