Danfoss VLT FC 102 Programming Manual

Also see for VLT HVAC Drive FC 102: Operating instructions Service guide Programming guide Installation guide Installation guide

Contents

1-72 Start FunctionOption: Function:[0] DC Hold/Motor PreheatEnergizes the motor with a DCholding current (parameter 2-00 DCHold/Preheat Current) during thestart delay time.[2] Coast Releases the shaft-coastedfrequency converter during thestart delay time (inverter off).Available selections depend onparameter 1-10 Motor Construction:[0] Asynchron:[2] Coast[0] DC-hold[1] PM non-salient:[2] coast1-73 Flying StartOption: Function:This function enables catching amotor which is spinning freely dueto a mains drop-out.When parameter 1-73 Flying Start isenabled, parameter 1-71 Start Delayhas no function.Search direction for flying start islinked to the setting inparameter 4-10 Motor SpeedDirection.[0] Clockwise: Flying start searchesin clockwise direction. If notsuccessful, a DC brake is activated.[2] Both Directions: The flying startfirst makes a search in the directiondetermined by the last reference(direction). If the speed is notfound, it makes a search in theother direction. If not successful, aDC brake is activated in the timeset in parameter 2-02 DC BrakingTime. Start then takes place from 0Hz.[0] Disabled Select [0] Disable if this function isnot required.[1] Enabled Select [1] Enable to enable thefrequency converter to catch andcontrol a spinning motor.The parameter is always set to [1]Enable when parameter 1-10 MotorConstruction=[1] PM non-salient.Important related parameters:1-73 Flying StartOption: Function:• Parameter 1-58 Flying StartTest Pulses Current• Parameter 1-59 Flying StartTest Pulses Frequency• Parameter 1-70 Start Mode• Parameter 2-06 ParkingCurrent• Parameter 2-07 ParkingTime• Parameter 2-03 DC BrakeCut In Speed [RPM]• Parameter 2-04 DC BrakeCut In Speed [Hz]• Parameter 2-06 ParkingCurrent• Parameter 2-07 ParkingTime[2] EnabledAlwaysEnable at every start.[3] Enabled Ref.Dir.Enable after coast, search inreference direction only.[4] Enab. AlwaysRef. Dir.Enable at every start, search inreference direction only.The flying-start function used for PM motors is based onan initial speed estimation. The speed is always estimatedas the 1st thing after an active start signal is given. Basedon the setting of parameter 1-70 Start Mode the followinghappens:Parameter 1-70 Start Mode=[0] Rotor Detection:If the speed estimate appears as greater than 0 Hz, thefrequency converter catches the motor at that speed andresumes normal operation. Otherwise, the frequencyconverter estimates the rotor position and start normaloperation from there.Parameter 1-70 Start Mode=[1] Parking:A speed estimate lower than the setting inparameter 1-59 Flying Start Test Pulses Frequency engagesthe parking function (see parameter 2-06 Parking Currentand parameter 2-07 Parking Time). Otherwise, the frequencyconverter catches the motor at that speed and resumesnormal operation. Refer to the description ofparameter 1-70 Start Mode for recommended settings.Current limitations of the flying-start principle used for PMmotors:• The speed range is up to 100% nominal speed orthe field weakening speed (whichever is lowest).• PMSM with high back EMF (>300 VLL(rms)) andhigh winding inductance (>10 mH) needs moreParameter Descriptions Programming GuideM0010001 Danfoss A/S © 10/2019 All rights reserved. 633 3