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Rigid metal conduit can be used as the shield of the motor wires. Always
observe the following points:
• Remove all paint from the control cabinet and motor housing where
the conduit is fastened.
• Securely fasten all conduit ttings.
• Run only the motor wires through the conduit, all other wires, high voltage
AC and low voltage signal, should be pulled through a separate conduit.
• Connect the control panel to the Sub-panel with a heavy ground strap.
Should EMI lters be used, they should be mounted to the inverter or as close
as possible to the inverter and on the same sub-panel as the inverter. Good
metallic surface contact to the sub-panel is required to provide adequate high
frequency grounding of the lter. Always use the shielding plate provided with
the lter when connecting the lter to the inverter.
Shielding of control wires:
• If digital signal wires are terminated on a terminal block in the control
panel, the shields should be rmly connected to the sub-panel on both
sides of the terminal block.
• The shields of digital signal wires originating outside the control cabinet
which are not terminated on a terminal block, must be connected to the
sub-panel at the point where the cable enters the control panel and at
the inverter.
• If the shield is terminated to the sub-panel within 8 inches (20cm) of the
inverter, then the shield no longer needs to be connected to the inverter.
• When using un-shielded signal wires, they should always be installed
as a twisted pair (signal and common).
• Low voltage signal wires should cross high voltage wires at right angles
Electrical Connection
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