Danfoss vlt soft starter mcd 500 Operating Manual

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Danfoss vlt soft starter mcd 500 Operating Manual Manual pdf 38 page image

5.2 Adaptive ControlAdaptive control is motor control based on theperformance characteristics of the motor. With adaptivecontrol, select the starting or stopping profile that bestmatches the load type. The soft starter automaticallycontrols the motor to match the profile. The VLT® SoftStarter MCD 500 offers 3 profiles:• Early acceleration and deceleration.• Constant acceleration and deceleration.• Late acceleration and deceleration.Adaptive control uses 2 algorithms; 1 to measure themotor characteristics, and 1 to control the motor. The softstarter uses the first start to determine the motor charac-teristics at zero speed and at maximum speed. During eachsubsequent start and stop, the soft starter dynamicallyadjusts its control to ensure that the actual motorperformance matches the selected profile throughout thestart. If the actual speed is too low for the profile, the softstarter increases power to the motor. If the speed is toohigh, the soft starter decreases power.5.3 Starting Modes5.3.1 Constant CurrentConstant current is the traditional form of soft starting. Itraises the current from zero to a specified level and keepsthe current stable at that level until the motor hasaccelerated.Constant current starting is ideal for applications where thestart current must be kept below a specific level.700%600%500%300%100%400%200%10% 20% 30% 40% 50%Rotor speed (% full speed)60% 70% 80% 90% 100% 177HA289.11Current (% motor full load current)1321 Parameter 1-5 Initial current2 Parameter 1-4 Current limit3 Full voltage currentIllustration 5.2 Example of Constant Current5.3.2 Current RampCurrent ramp soft starting raises the current from aspecified starting level (1) to a maximum limit (3), over anextended period (2).Current ramp starting can be useful for applications where:• The load can vary between starts (for example aconveyor which may start loaded or unloaded).Set parameter 1-5 Initial Current to a level thatstarts the motor with a light load. Set parameter1-4 Current Limit to a level that starts the motorwith a heavy load.• The load breaks away easily, but starting timemust be extended (for example a centrifugalpump where pipeline pressure must build upslowly).• The electricity supply is limited (for example agenerator set), and a slower application of loadallows greater time for the supply to respond.700%600%500%300%100%400%200%10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 177HA290.10CURRENT (% Motor Full Load Current)ROTOR SPEED (% Full Speed)Full Voltage Stator CurrentCurrent Limit (e.g. Par. 2 = 400% x FLC)Initial Current (e.g. Par. 3 = 250% x FLC)Ramp Time(eg Par. 4 = 10 secs)1 Parameter 1-5 Initial current2 Parameter 1-6 Start ramp time3 Parameter 1-4 Current limit4 Full voltage currentIllustration 5.3 Example of a 10 s Current Ramp TimeProduct Features VLT® Soft Starter MCD 50036 Danfoss A/S © 05/2016 All rights reserved. MG17K60255