3-18 Installing the Converter
590D DC Digital Converter - HA467078
Connection Details
The connection between the Converter, choke and filter must always be as short as possible and
must be segregated from all other cables. Ideally, mount the filter and choke onto the same
metallic panel as the Converter. Take care not to obstruct any ventilation spacing.
If this cable/busbar exceeds 0.6m in length, it must be replaced with a screened/armoured cable.
The screen/armour must be earthed at both the filter, choke and Converter ends with large-area
contact surfaces, preferably with metal cable glands.
You should enhance the RF connection between the Converter, choke, filter and panel as
follows:
1. Remove any paint/insulation between the mounting points of the EMC filter, choke,
Converter and the panel. Liberally apply petroleum jelly over the mounting points and
securing threads. This will prevent corrosion. Alternatively, conducting paint could be used
on the panel.
2. If 1 above is not possible, then improve the RF earth bond between the filter and Converter
by making an additional RF earth connection. Use wire braid of at least 10mm² cross-
sectional area.
Note:
Metal surfaces, such as anodised or yellow chromed (with cable mounting or 35mm
DIN rails, screws and bolts) have a high impedance which can be very detrimental to
EMC performance.
3. A low RF impedance path must be provided between the motor frame and back panel on
which the drive, choke and EMC filters are mounted. This low impedance RF path should
follow the path of the motor cables in order to minimise the loop area. Failure to do so will
result in increased conducted emissions.
A low RF impedance path will normally be achieved by:
Bonding the armour of the motor supply cables at one end to the motor frame, and at the
other end to the cubicle back panel. Ideally 360
o
bonding is required, which can be achieved
with cable glands, refer to
32
HFigure 3-3 360 Degree Screened Connection, page 3-
33
H3.
Ensuring that conduit containing the motor supply cables are bonded together using braid.
The conduit should also be bonded to the motor frame and the cubicle back panel.
Earthing Details
The protective earth (PE) conductor exiting the filter must be connected to the protective earth
connection of the Converter. Any additional RF earth, such as a cable screen, is not a
protective earth. The EMC filter must be permanently earthed to prevent the risk of electric
shock under abnormal operating instances (such as the loss of one phase of the ac supply).
You can achieve permanent earthing by either:
• using a copper protective earth conductor of at least 10mm²
• installing a second conductor, in parallel connection with the protective conductor, to a
separate protective earth terminal
Each conductor must independently meet the requirements for a protective earth conductor.
Operating Conditions
The recommended EMC filters operate from normal three-phases supplies which are balanced
with respect to earth (earth referenced supplies - TN). This minimises the earth leakage current
due to the filter capacitors between phase and earth.
IMPORTANT: We do not recommend the use of ac supply filters on non earth-referenced supplies - IT.
The supplies cause earth leakage currents to increase, and interfere with the operation of
earth fault monitoring equipment. In addition, EMC performance of the filter is
degraded.
As with all power electronic drives, conducted emissions increase with motor cable length.
EMC conformance is only guaranteed up to a cable length of 50m. The cable length can be
increased. Refer to Parker SSD Drives for more information.
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