Danfoss AHF005 Design Manual

Also see for VLT AHF 005: Instruction manual Operating instructions Operating instructions Design guide

Contents

Danfoss AHF005 Design Manual Manual pdf 25 page image

6.2 Electrical Installation6.2.1 Over Temperature ProtectionThe Danfoss harmonic filters AHF005 and AHF010 are allequipped with a galvanic isolated switch (PELV) that is closedunder normal operating conditions and open if the filter isoverheated.NOTEThe over temperature protection must be used toprevent damage of the filter caused by over tempera-ture. An immediate stop or a controlled ramp downwithin max. 30 s has to be performed to prevent filterdamage.There are many ways the switch can be used and one exampleis to connect terminal A of the harmonic filter to terminal 12 or13 (voltage supply digital input, 24 V) of the Danfoss frequen-cy converter and terminal B to terminal 27. Program digitalinput terminal 27 to Coast Inverse. The frequency converterwill coast the motor and thereby unload the filter if an overtemperature is detected. Alternatively use terminal 12/33 andset par. 1-90 to motor terminal protection.NOTEThe maximum rating of the over temperature contactoris 250 V AC and 10 A.6.2.2 Capacitor DisconnectThe power factor of the harmonic filter AHF 005/010 isdecreasing with decreasing load. At no load the power factoris zero and the capacitors produce leading current of approx-imately 25 % of rated the filter current. In applications wherethis reactive current is not acceptable the terminals X3.1, X3.2,X3.3 and X4.1, X4, X4.3 provide access to the capacitor bank,so it can be disconnected.Default (on delivery) the wiring will shorten terminal X3.1 withX4.1, X3.2 with X4.2 and X3.3 with X.4.3. In the case that nocapacitor disconnect is required, no changes should be madeto these shorted terminals.If a disconnection of the capacitors is required a three-phasecontactor should be placed between terminals X3 and X4. It isrecommended to use AC3 contactors.How to Install AHF005/010 Design GuideMG.80.C3.02 - VLT® is a registered Danfoss trademark 256 6