ACH550-UH User’s Manual
235
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).
Clamp the cable shield into the gland plate at the drive end. Twist the cable screen
wires together into a bundle not longer than five times its width and connect it to the
terminal marked
(at the bottom right-hand corner of the drive).
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.
EN61800-3 Compliant Motor Cables
To comply with EN61800-3, First and Second Environment (Restricted Distribution)
requirements, motor cables:
•
Less than or equal to 30 m (100 ft) do not require an RFI/EMC filter.
•
Must have an effective screen as described in "Effective Motor Cable Screens" on
page 235.
•
Must be earthed, at the motor end, with an EMC cable gland.The earthing must
contact the cable screen all the way around the cable.
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
