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4-4 Regenerative Energy Absorption
Accurax G5 AC SERVOMOTOR AND SERVO DRIVE USER'S MANUAL
   4
System Design
Regenerative Energy Absorption with an External Regeneration Resistor
If the regenerative energy exceeds the regeneration absorption capacity of the driver, connect
an External Regeneration Resistor.
Connect the External Regeneration Resistor between B1 and B2 terminals on the driver.
Double-check the terminal names when connecting the resistor because the driver may be
damaged if connected to the wrong terminals.
The External Regeneration Resistor will heat up to approx. 120°C. Do not place it near
equipment and wiring that is easily affected by heat. Attach radiator plates suitable for the heat
radiation conditions.
External Regeneration Resistor
Characteristics
Model
Resistance 
value
Nominal 
capacity
The amount of 
regeneration 
absorption for 120
°
C 
temperature rise
Heat 
radiation 
condition
Thermal switch output 
specifications
R88A-
RR08050S
50 Ω 80 W 20 W
Aluminum 
250 × 250,
Thickness: 3.0
Operating temperature 
150°C ± 5% NC contact
Rated output: 30 VDC, −
50 mA max.
R88A-
RR080100S
100 Ω 80 W 20 W
Aluminum 
250 × 250,
Thickness: 3.0
Operating temperature 
150°C ± 5% NC contact
Rated output: 30 VDC, −
50 mA max.
R88A-
RR22047S
47 Ω 220 W 70 W
Aluminum 
350 × 350,
Thickness: 3.0
Operating temperature: 
170 ± 7°C
NC contact
Rated output: 250 VAC, 
0.2 A max.
R88A-
RR50020S
20 Ω 500 W 180 W
Aluminum 
600 × 600,
Thickness: 3.0
Operating temperature 
200 ± 7°C
NC contact
Rated output: 250 VAC, 
0.2 A max.
24 VDC, 0.2 A max.