DigitAx User Guide
Issue code: dgxu4
4-1
4 Mechanical Installation
Warning
The equipment enclosure is
rated at IP20 in accordance
with IEC539. It is designed
for installation within a
protective enclosure which
prevents unauthorised
access except for trained
service personnel, and
prevents contamination with
conductive dust and
condensation.
4.1 EMC wiring
recommendations
To minimize radio-frequency emissions, it is
necessary to install the Drive in a steel enclosure and
pay attention to the arrangement of the wiring
inside the enclosure. Figure 4–1 shows
recommendations for the layout of the enclosure.
Figures 5–1 and 5–3 in Chapter 5 Electrical Installation
show examples of wiring arrangements for minimum
radio-frequency emissions. The actual arrangement
will have to be adapted to individual requirements.
When planning the installation, refer to Chapter 5 in
addition to this chapter.
The essential requirements are as follows:
RFI filter
• Mount an RFI filter above the Drive at a
distance of 125mm (5 in).
• Make the AC power cables from the RFI
filter to the Drive as short as possible.
• Use a flat conductor at least 10mm (
1
/2in)
wide and as short as possible to make the
ground connection from the RFI filter to the
Drive.
Motor cable
• Use armoured or shielded cable to connect
the motor to the Drive. Connect the
armour or shield to the Drive and to the
motor frame. Make these connections no
longer than 50mm (2in).
• If the length of cable used to connect the
motor to the Drive exceeds 50m (150 feet),
output chokes may be required in order to
prevent cable capacitance effects causing
over-current trips (OC) in the Drive. For
difficult cases, consult the supplier of the
Drive.
Resolver wiring
Simulated-encoder wiring
• Signal connections from the resolver and
from the simulated encoder input of the
CNC controller must be connected to the
Drive using cable consisting of three
twisted-pairs of wire. Each twisted pair
must be screened, and the cable must have
an overall screen. Connect the screens of
the resolver cable only to terminal B18 of the
Drive. Connect the screens of the simulated
encoder output only to the CNC controller
ground terminal.
• When a motor thermistor is to be used,
connect it to the Drive using a fourth
twisted-pair in the screened cable to the
resolver. Connect the screen for this
twisted-pair only to terminal B18 on the
Drive.
Analog speed reference wiring
• Use shielded twisted-pair cable to connect
the analog speed reference to the Drive. It
is strongly recommended that a true
differential signal source is used in order to
maximize immunity to electrical noise.
Connect the cable shield only to the ground
connection of the CNC controller.
• A single-ended signal source may be used,
but electrical noise immunity is reduced.
Use shielded twisted-pair cable. Apply the
signal to terminal B9 or B10 of the Drive, as
required. Connect the 0V common to
terminal B11. Connect the unused
differential input (terminal B10 or B9) to
terminal B11.
Ground connections
• Bus-bars must be used to make certain
ground connections, as shown in Figure 5–4.
These bus-bars must be made of copper bar
of the dimensions shown.
Ferrite absorber ring
• When a number of Drives are installed in an
enclosure, it is recommended that a ferrite
absorber ring is fitted over the AC supply
cables to each Drive. (See also Capacitor
network.)
• Part numbec: 4200-3608
Capacitor network
• When three or more Drives are installed in
an enclosure, a capacitor network may be
required. Refer to Figure 5–4.