User manual

Chapter 6 Control Modes of Operation ASDA-A User Manual
4th Edition 2005/11/30, HE03 © DELTA ELECTRONICS, INC. ALL RIGHTS RESERVED
6-40
6-6-3 Regenerative Resistor
Built-in Regenerative Resistor
When the output torque of servo motor in reverse direction of motor rotation speed, it indicates that there is a
regenerative power is returned from the load to the servo drive. This power will be transmitted into the
capacitance of DC Bus and result in rising voltage. When the voltage has risen to some high voltage, using
regenerative resistor can dischange. ASDA-A series servo drive provides built-in regenerative resistor but
user also can connect to external regenerative resistor.
The following table shows the specifications of the servo drive’s built-in regenerative resistor and the amount
of regenerative power (average value) that it can process.
Built-in Regenerative Resistor
Specifications
Servo Drive
(kW)
Resistance (Ohm)
(parameter P1-52)
Capacity (Watt)
(parameter P1-53)
Regenerative Power
processed by built-in
regenerative resistor
(Watt) *
1
Min. Allowable
Resistance (Ohm)
0.1 40 60
30 40
0.2 40 60 30 40
0.4 40 60 30 20
0.75 40 60 30 20
1.0 40 60 30 20
1.5 40 60 30 20
2.0 20 120 60 10
3.0 20 120 60 10
*1: Regenerative power calculation: The amount of regenerative power (average value) that can be
processed is rated at 50% of the capacity of the servo drive’s built-in regenerative resistor. The
regenerative power calculation method of external regenerative resistor is the same.
When the regenerative power exceeds the processing capacity of the servo drive, install an external
regenerative resistor. Please pay close attention on the following notes when using a regenerative resistor.
1. Make sure that the settings of resistance (parameter P1-52) and capacity (parameter P1-53) is set
correctly.
2. When user wants to install an external regenerative resistor, ensure that its resistance value is the same
as the resistance of built-in regenerative resistor. If combining multiple small-capacity regenerative
resistors in parallel to increase the regenerative resistor capacity, make sure that the resistance value of
the regenerative resistor should comply with the specifications listed in the above table.
3. In general, when the amount of regenerative power (average value) that can be processed are used at or
below the rated load ratio, the resistance temperature will increase to 120°C or higher (on condition that
when the regeneration continuously occurred). For the safety reason, forced air cooling is good way that
can be used to reduce the temperature of the regenerative resistors. We also recommend you to use the
regenerative resistors with thermal switches. As for the load characteristics of the regenerative resistors,
please check with the manufacturer.