Yaskawa SGDS Sigma III Servo Amplifier - Manual (Page 128)

5.7 Connecting Regenerative Resistors
5-25
5.7 Connecting Regenerative Resistors
5.7.1 Regenerative Power and Regenerative Resistance
The rotational energy of driven machine such as servomotor is returned to the SERVOPACK. This is called
regenerative power. The regenerative power is absorbed by charging the smoothing capacitor, but if the amount
of power exceeds the capacity of the capacitor, the regenerative power is further consumed by the regenerative
resistor.
The servomotor is driven in regeneration state in the following circumstances:
• While decelerating to a stop during acceleration and deceleration operation.
• Continuous descending operation on the vertical axis
• During continuous operation with the servomotor rotated from the load side (negative load).
The SERVOPACKs with a capacity of the single-phase 200 V with 30 to 400 W or 100 V with 50 to 400 W do
not have built-in regenerative resistors. If the operation exceeds the rotating speed specifications shown in the
3.5.3 Load Moment of Inertia, connect an external regenerative resistor.
5.7.2 Connecting Externally Regenerative Resistors
(1) Necessity of External Regenerative Resistors
(2) Specifications of Built-in Regenerative Resistor
If the amount of regenerative energy exceeds the processing capacity of the SERVOPACK, then install an
external regenerative resistor. The following table shows the specifications of the SERVOPACK’s built-in
resistor and the amount of regenerative power (average values) that it can process.
* The average regenerative power that can be handled is 20% of the rated capacity of the regenerative
resistor built into the SERVOPACK.
SERVOPACK
Capacity
Necessity of External Regenerative Resistors
400 W or less
No built-in regenerative resistor is provided, however, normally an external regenerative
resistor is not required.
Install external regenerative resistors when the smoothing capacitor in SERVOPACK cannot
process all the regenerative power.
1.0 to 3.0 kW
A built-in regenerative resistor is provided as standard. Install external regenerative
resistors when the built-in regenerative resistor cannot process all the regenerative power.
Main Circuit
Power
SERVOPACK Model Specifications
of Built-in Resistor
Regenerative
Power Processed
by Built-in Resistor ∗
(W)
Minimum
Allowable
Resistance
( Ω)
Capacity
(kW)
SGDS- Resistance
( Ω)
Capacity
(W)
Single-
phase
100 V
0.05 A5F
not available not available −
40
0.10 01F
0.20 02F
0.40 04F
Single-
phase
200 V
0.05 A5A
not available not available −
0.10 01A
0.20 02A
0.40 04A
0.80 08A
50
60 12
Three-
phase
200 V
1.0 10A 60 12
1.5 15A 30 70 14 20
2.0 20A 25 140 28 12
3.0 30A 12.5 140 28 12