ACS550 User’s Manual
227
Technical Data
Recommendation for Conductor Layout
The following figure compares conductor layout features in motor cables.
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).
EN 61800-3 Compliant Motor Cables
To comply with EN 61800-3
requirements:
•
Motor cables must have an effective screen as described in "Effective Motor
Cable Screens" on page 227.
•
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 bottom right-hand corner of the drive).
•
Motor cables must be grounded, at the motor end, with an EMC cable gland. The
ground must contact the cable screen all the way around the cable.
•
For EN 61800-3 First Environment, Restricted Distribution (CISPR11 Class A),
and EN 61800-3 Second Environment compliance, the drive includes an internal
filter that provides compliance for at least 30 m (100 ft.) motor cable lengths. For
some drives, longer cable lengths require an additional, external RFI/EMC filter
as specified in the table below. The RFI/EMC filters are separate options and
Symmetrical shielded cable: three phase
conductors and a concentric or otherwise
symmetrically constructed PE conductor, and a
shield
Recommended
(CE & C-Tick)
PE
Conductor
and Shield
A separate PE conductor is required if the
conductivity of the cable shield is < 50% of the
conductivity of the phase conductor.
Not allowed for motor cables
(CE & C-Tick)
Shield
PE
PE
Allowed for motor cables
with phase
conductor cross section up to 10 mm
2
.
A four-conductor system: three phase
conductors and a protective conductor, without a
shield.
Allowed
(CE & C-Tick)
Shield
Shield
Insulation Jacket
Braided Metallic Screen
Inner Insulator
L1
L2
L3
