KEB COMBIVERT F5 Instruction Manual

Also see for COMBIVERT F5: INSTALLATION GUIDELINE Installation manual Instruction manual Instruction manual Installation manual

Contents

17General1.4.10 High Frequency ShieldingUse of shielded cable is recommended when high frequency emissions or easilydisturbed signals are present. Examples are as follows:- motor wires: connect shield to ground at both the drive and motor, NOTEthe shield should never be used as the protective ground conductor requiredby NFPA70 or CSA22.1. Always use a separate conductor for this.- digital control wires: connect shield to ground at both ends.- analog control wires: connect shield to ground only at the inverter.The connection of meshed shields to the ground connection should not bedone through a single strand or drain wire of the shield, but with metallic clampsto provide 360° contact around the surface of the shield to the ground point.Connection with a single wire from the braided shield reduces the effectiveness ofthe shield 70%. Metal conduit clamps work well for this. Be sure the fit is tight.Ridged metal conduit can be used as the shield of the motor wires. Alwaysobserve the following points :- remove all paint from the control cabinet and motor housing where theconduit is fastened- securely fasten all conduit fittings- run only the motor wires through the conduit, all other wires, high voltage ACand low voltage signal, should be pulled through a separate conduit.- connect the control panel to the Sub-panel with a heavy ground strap.If EMI filters are used, they should be mounted to the inverter or as close aspossible to the inverter and on the same sub-panel as the inverter. Good metallicsurface contact to the sub-panel is required to provide adequate high frequencygrounding of the filter. Always use the shielding plate provided with the filter whenconnecting the filter 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 firmly connected to the sub-panel on both sides of theterminal block.The shields of digital signal wires originating outside the control cabinet whichare not terminated on a terminal block, must be connected to the sub-panel atthe 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 theinverter, then the shield no longer needs to be connected to the inverter.When using un-shielded signal wires, they should always be installed as atwisted pair (signal and common).Low voltage signal wires should cross high voltage wires at right angles.