Recommendation For Conductor Layout; Effective Motor Cable Screens; En 61800-3 Compliant Motor Cables - ABB ACS550 User Manual

ACS550 User's Manual

Recommendation for conductor layout

The following figure compares conductor layout features in motor cables.
Symmetrical shielded cable: three phase
conductors and a concentric or otherwise
symmetrically constructed PE conductor, and a
shield
Not allowed for motor cables (CE & C-Tick)
A four-conductor system: three phase
conductors and a protective conductor, without a
shield.

Effective motor cable screens

The general rule for cable screen effectiveness is: the better and tighter the cable's
screen, the lower the radiated emission level. The following figure shows an
example of an effective construction (for example Ölflex-Servo-FD 780 CP,
Lappkabel or MCCMK, NK Cables).
Insulation jacket

EN 61800-3 compliant motor cables

The most efficient EMC filtering can be achieved by following these rules:
• Motor cables must have an effective screen as described in section
motor cable screens
• Motor cable screen wires must be twisted together into a bundle (the bundle
length must be less than five times its width) and connected it to the terminal
marked
• At the motor end, the motor cable screen must be earthed 360 degrees with an
EMC cable gland, or the screen wires must be twisted together into a bundle not
longer than five times its width and connected to the PE terminal of the motor.
• See section
272
drives for IEC/EN 61800-3 compliance.
Recommended (CE & C-Tick)
PE
conductor
and shield
PE
Braided metallic screen
on page 275.
(at the bottom right-hand corner of the drive).
Motor cable length for 400 V
to check the maximum motor cable lengths and the need for filters for 400 V
Allowed (CE & C-Tick)
A separate PE conductor is required if the
conductivity of the cable shield is < 50% of the
conductivity of the phase conductor.
Shield
Allowed for motor cables with phase
conductor cross section up to 10 mm
Inner insulator
L2
L1
L3
drives, columns
275
Shield
PE
Shield
2
.
Effective
"EMC limits" on page
Technical data