Variations In The Emc Wiring Recommendations - Control Techniques Unidrive LV Series Installation Manual

2.8 Variations in the EMC
wiring recommendations
Control wiring
Control wiring which is connected to the Drive and
leaves the enclosure must have one of the following
additional treatments:
•
Pass the control cable(s) through a ferrite
ring (part number 3225-1004). More than
one cable can pass through a ferrite ring.
Ensure the length of cable between the
ferrite ring and the Drive is not greater than
125mm (5 in).
•
Use one or more cables having a separate
overall shield. Bond this shield(s) to the
back-plate using an uninsulated metal clamp.
Position the clamp not further than 100mm
(4 in) from the Drive. Do not make any
other connections to either end of the
overall shield.
Interruptions to the motor cable
The motor cable should ideally be a single piece of
shielded or armoured cable having no interruptions.
In some situations it may be necessary to interrupt
the cable, as in the following examples:
Connecting the motor cable to a terminal block
in the Drive enclosure
Fitting a motor isolator switch for safety when
work is done on the motor
In these cases the following guidelines should be
followed.
2-36 Installing the Drive
Terminal block in the enclosure
The motor cable shields should be bonded to the
back-plate using uninsulated metal cable-clamps
which should be positioned as close as possible to
the terminal block. Keep the length of power
conductors to a minimum and ensure that all
sensitive equipment and circuits are at least 0.3m
(12 in) away from the terminal block.
(Refer to Key to symbols in Figure 2–22)
Figure 2–24 Connecting the motor cable to
a terminal block in the enclosure
Unidrive LV model sizes 1 to 3 Installation Guide
From the Drive
Back-plate
Enclosure
To the motor
Issue code: uliu1