Danfoss VLT AQUA Drive Operating Instructions Manual

Also see for vlt aqua: Instructions Design guide Instruction manual Design guide Operating instructions

5.1.8. Mains connection for C1 and C2Illustration 5.11: How to connect to mains and earthing.5.1.9. How to connect motor - forewordSee sectionGeneral Specifications for correct dimensioning of motor cable cross-section and length.• Use a screened/armoured motor cable to comply with EMC emission specifications (or install the cable in metal conduit).• Keep the motor cable as short as possible to reduce the noise level and leakage currents.• Connect the motor cable screen/armour to both the decoupling plate of the frequency converter and to the metal of the motor. (Same appliesto both ends of metal conduit if used instead of screen.)• Make the screen connections with the largest possible surface area (cable clamp or by using an EMC cable gland). This is done by using thesupplied installation devices in the frequency converter.• Avoid terminating the screen by twisting the ends (pigtails), as this will spoil high frequency screening effects.• If it is necessary to break the continuity of the screen to install a motor isolator or motor relay, the continuity must be maintained with the lowestpossible HF impedance.Cable length and cross-sectionThe frequency converter has been tested with a given length of cable and a given cross-section of that cable. If the cross-section is increased, the cablecapacitance - and thus the leakage current - may increase, and the cable length must be reduced correspondingly.Switching frequencyWhen frequency converters are used together with sine wave filters to reduce the acoustic noise from a motor, the switching frequency must be setaccording to the sine wave filter instruction in par. 14-01.Precautions while using Aluminium conductorsAluminium conductors are not recommended for cable cross sections below 35 mm². Terminals can accept aluminium conductors but the conductorsurface has to be clean and the oxidation must be removed and sealed by neutral acid free Vaseline grease before the conductor is connected.Furthermore, the terminal screw must be retightened after two days due to the softness of the aluminium. It is crucial to ensure the connection makesa gas tight joint, otherwise the aluminium surface will oxidize again.VLT® AQUA DriveOperating Instructions 5. Electrical installationMG.20.M4.02 - VLT® is a registered Danfoss trademark 315