Danfoss VT2800 Series Design Manual

Contents

VLT ® 2800 SeriesDescription of choice:Set the necessary time for which a highstart torque is required.120 Start delay(START DELAY)Value:0.0 - 10.0 sec. ✭ 0.0 sec.Function:This parameter enables a delay of the start-up timeafter the conditions for start have been fulfilled.When the time has passed, the output frequencywill start by ramping up to the reference.Description of choice:Set the necessary time before commencingto accelerate.121 Start function(START FUNCTION)Value:DC hold during start delay time(DC HOLD/DELAY TIME) [0]DC brake during start delay time(DC BRAKE/DELAY TIME) [1]✭Coasting during start delay time(COAST/DELAY TIME) [2]Start frequency/voltage clockwise(CLOCKWISE OPERATION) [3]Start frequency/voltage in reference direction(VERTICAL OPERATION) [4]Function:This is where to choose the required mode during thestart delay time (parameter 120 Start delay time).Description of choice:Select DC hold during start delay time [0] to energizethe motor with a DC hold voltage during the start delaytime. Set voltage in parameter 137 DC hold voltage.Choose DC brake during start delay time [1] to energizethe motor with a DC brake voltage during the start delaytime. Set voltage in parameter 132 DC brake voltage.Choose Coasting during start delay time [2] and themotor will not be controlled by the frequency converterduring the start delay time (inverter turned off).Choose Start frequency/voltage clockwise [3] toobtain the function described in parameter 130Start frequency and 131 Voltage at start during startdelay time. Regardless of the value assumed bythe reference signal, the output frequency equalsthe setting in parameter 130 Start frequency andthe output voltage will correspond to the settingin parameter 131 Voltage at start .This functionality is typically used in hoist applications.It is used in particular in applications in which a coneanchor motor is applied, where the direction of rotationis to start clockwise followed by the reference direction.Select Start frequency/voltage in reference direction[4] to obtain the function described in parameter130 Start frequency and 131 Voltage at startduring the start delay time.The direction of rotation of the motor will alwaysfollow in the reference direction. If the reference signalequals zero, the output frequency will equal 0 Hz,while the output voltage will correspond to the settingin parameter 131 Voltage at start. If the referencesignal is different from zero, the output frequency willequal parameter 130 Start frequency and the outputvoltage will equal parameter 131 Voltage at start. Thisfunctionality is used typically for hoist applications withcounterweight. It is used in particular for applicationsin which a cone anchor motor is applied. The coneanchor motor can break away using parameter 130Start frequency and parameter 131 Voltage at start.122 Function at stop(FUNCTION AT STOP)Value:✭Coasting (COAST) [0]DC hold (DC HOLD) [1]Function:This is where to choose the function of the frequencyconverter after the output frequency has becomelower than the value in parameter 123 The min.frequency for activation of function at stop or aftera stop command and when the output frequencyhas been ramped down to 0 Hz.Description of choice:Select Coasting [0] if the frequency converter is to’let go’ of the motor (inverter turned off).Select DC hold [1] if parameter 137 DC holdvoltage is to be activated.✭ = factory setting. () = display text [] = value for use in communication via serial communication portMG.28.E9.02 - VLT is a registered Danfoss trademark72