Nidec DFS Series Power Installation Manual

DFS1/DFS2 Power Installation Guide 51Issue Number: 2Safety information Product information Mechanical installation Electrical installation Technical dataTerminal block in the enclosureThe motor cable shields should be bonded to a back-plate using uninsulated metal cable-clampswhich should be positioned as close as possible to the terminal block. Keep the length of powerconductors to a minimum and ensure that all sensitive equipment and circuits are at least 0.3 m(12 in) away from the terminal block.Figure 4-11 Installing a terminal block in the motor cableUsing a motor isolator/disconnect-switchThe motor cable shields should be connected by a very short conductor having a low inductance.The use of a flat metal coupling-bar is recommended; conventional wire is not suitable.The shields should be bonded directly to the coupling-bar using uninsulated metal cable-clamps.Keep the length of the exposed power conductors to a minimum and ensure that all sensitiveequipment and circuits are at least 0.3 m (12 in) away.The coupling-bar may be grounded to a known low-impedance ground nearby, for example a largemetallic structure which is connected closely to the drive ground.Figure 4-12 Connecting the motor cable to an isolator/disconnect switch4.22.6 Surge immunity of control circuitsThe input/output ports for the control circuits are designed for general use within machines and smallsystems without any special precautions.These circuits meet the requirements of EN 61000-6-2:2005 (1 kV surge) provided the 0 Vconnection is not grounded.From the DriveTo the motorBack-plateEnclosureIsolatorCoupling barFrom theDriveTo themotor(If required)