Current Ramp; Aac Adaptive Acceleration Control - Danfoss mcd-500 Operating Instruction

5 Application Examples

5.3.2 Current Ramp

Current ramp soft starting raises the current from a specified starting level (1) to a maximum limit (3), over an extended period of time (2).
Current ramp starting can be useful for applications where:
• the load can vary between starts (for example a conveyor which may start loaded or unloaded). Set the initial current (Par. 1-5) to a level that
will start the motor with a light load, and the current limit (Par. 1-4) to a level that will start the motor with a heavy load.
• the load breaks away easily, but starting time needs to be extended (for example a centrifugal pump where pipeline pressure needs to build up
slowly).
• the electricity supply is limited (for example a generator set), and a slower application of load will allow greater time for the supply to respond.
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5.3.3 AAC Adaptive Acceleration Control

To use AAC Adaptive Acceleration Control to control starting performance:
1. Select Adaptive Control from the Start Mode menu (Par. 1-3)
2. Set the desired Start Ramp Time (Par. 1-6)
3. Select the desired Adaptive Start Profile (Par. 1-13)
4. Set a start Current Limit (Par. 1-4) sufficiently high to allow a successful start. The first AAC start will be a Constant Current start. This allows
the MCD 500 to learn the characteristics of the connected motor. This motor data is used by the MCD 500 during subsequent AAC Adaptive
Acceleration Control starts.
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Full Voltage Stator Current
Ramp Time
(eg Par. 4 = 10 secs)
Current Limit (e.g. Par. 2 = 400% x FLC)
Initial Current (e.g. Par. 3 = 250% x FLC)
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MCD 500 Operating Instruction
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