8 Applied Settings
8 - 50
High-function General-purpose Inverter RX2 Series User’s Manual
When decelerating, generating downward movement, or being rotated by an external load (that is,
when the output torque direction and the rotation direction are opposite), the motor serves as a genera-
tor and the regenerated energy is fed back to the inverter. If the motor load inertia is large, the amount
of regeneration may become large, which causes an overvoltage in the inverter during rapid decelera-
tion or when driving an elevating axis.
The regenerative braking function uses the built-in or an external regenerative braking circuit to
decrease the internal DC voltage of the inverter by converting the regenerated energy from the motor
into heat via external braking resistors.
Connect external braking resistors or external regenerative braking units according to the description of
External Braking Resistor Connection Terminal or Regenerative Braking Unit Connection Terminal in
2-3-4 Wiring for Main Circuit Terminals
on page 2-32. The regenerative braking function is enabled only
when the inverter is connected with external braking resistors or external regenerative braking units.
The following models have a built-in regenerative braking circuit. Connect external braking resistors
only.
[200-V class] 3G3RX2-A2004 (0.4 kW) to 3G3RX2-A2220 (22 kW)
[400-V class] 3G3RX2-A4007 (0.75 kW) to 3G3RX2-A4370 (37 kW)
When using models other than the above or processing a large amount of regenerative energy, you
need to use regenerative braking units.
When using the built-in regenerative braking function of the inverter, set BRD selection (bA-61) to
Enabled.
Normally, this parameter is set to 01 (Enabled: Disabled during stop). At this time, set the usage condi-
tion (%) of the braking resistor in use in the Usage Rate of BRD (bA-60). Note that the regenerative
braking function is enabled only when both bA-60 and bA-61 are set.
Be sure to set the resistance values of the connected braking resistor to Dynamic brake (BRD) resister
value [bA-63]. The resistance values are used with Dynamic brake (BRD) usage rate [bA-60] when the
regenerative braking function is activated.
For the Regenerative Braking ON Level (b096), you need not change the default data normally. This
parameter is used for adjusting the level at which the regenerative braking function according to the
input power supply voltage.
External regenerative braking units are processed on the external regenerative braking unit side.
Therefore, set the Regenerative Braking Selection (bA-61) to 00 (Disabled). In this case, the bA-60
and bA-62 settings are ignored.
When using this function, set the Overvoltage Suppression Function Selection During Deceleration
(bA140) to 00 (Disabled).
Precautions for Correct Use
• You can also use the optional BRD unit instead of using the built-in braking circuit (BRD). If
using the BRD unit, no setting needs to be made.
• The BRD ON level is the level setting for the main circuit DC smoothing capacitor inside the
inverter. It needs to be set to a value exceeding the input voltage times √2.
• See the selection and wiring of regenerative braking resistor for minimum resistance that can
be connected and BRD use rate for each model.
8-2-5
Regenerative Braking Function
Summary of Contents for RX - 2
Page 1: ...High function General purpose Inverter RX2 Series User s Manual I620 E1 01 3G3RX2...
Page 54: ...1 Overview 1 22 High function General purpose Inverter RX2 Series User s Manual...
Page 136: ...2 Design 2 82 High function General purpose Inverter RX2 Series User s Manual...
Page 592: ...8 Applied Settings 8 192 High function General purpose Inverter RX2 Series User s Manual...
Page 754: ...11 Options 11 56 High function General purpose Inverter RX2 Series User s Manual...
Page 794: ...12 Troubleshooting 12 40 High function General purpose Inverter RX2 Series User s Manual...
Page 919: ......
