Installing the Drive 3-61
DC590+ Series DC Digital Drive
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 360o
bonding is required, which can be achieved with cable glands, refer to
51HCable Gland Requirements52H, page 53H3-10.
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 Drive. 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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