Danfoss VT2800 Series Design Manual

Contents

VLT ® 2800 SeriesProgrammingFunction:This parameter can be set so that the internal fan isautomatically switched on and off. You can also setthe internal fan to be permanently switched on or off.Description of choice:If Automatic [0] is selected, the internal fan is switchedon or off depending on the ambient temperatureand the loading of the frequency converter.If Always switched on [1] Always switchedoff [2] are selected, the internal fan will bepermanently switched on or off.NB!:If Always switched off [2] is selected incombination with high switch frequency,long motor cables or high output power, thefrequency converter’s life span is reduced.144 Gain AC brake(GAIN AC BRAKE)Value:1.00 - 1.50 ✭ 1.30Function:This parameter is used to set the AC brake. Using par.144 it is possible to adjust the size of the generatortorque that can be applied to the motor without theintermediate circuit voltage exceeding the warning level.Description of choice:The value is increased if a greater possible braketorque is required. If 1.0 is selected, this correspondsto the AC brake being inactive.NB!:If the value in par. 144 is increased, themotor current will simultaneously increasesignificantly when generator loads are applied.The parameter should therefore only be changed ifit is guaranteed during measurement that the motorcurrent in all operating situations will never exceed themaximum permitted current in the motor. Please note:that the current cannot be read out from the display.146 Reset voltage vector(RESET VECTOR)Value:*Off (OFF) [0]Reset (RESET) [1]Function:When the voltage vector is reset it is set to the samestarting point each time a new process commences.Description of choice:Select reset (1) when running unique processes eachtime they arise. This will enable repetitive precisionwhen stopping to be improved. Select Off (0) forexample for lifting/lowering operations or synchronousmotors. It is an advantage that the motor and thefrequency converter are always synchronized.✭ = factory setting. () = display text [] = value for use in communication via serial communication portMG.28.E9.02 - VLT is a registered Danfoss trademark 77