Omron SMARTSTEP 2 R88M-G Series - Servo Drive Regenerative Energy Absorption Capacity; Absorbing Regenerative Energy with an External Regeneration Resistor

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4-4 Regenerative Energy Absorption
4
System Design
Servo Drive Regenerative Energy Absorption Capacity
The SMARTSTEP 2 Servo Drives absorb regenerative energy internally with built-in capacitors.
If the regenerative energy is too large to be processed internally, an overvoltage error (AL12) occurs
and operation cannot continue. The following table shows the regenerative energy (and amount of
regeneration) that each Servo Drive can absorb.
If these values are exceeded, take the following measures.
 Add an External Regeneration Resistor.
 Reduce the operating rotation speed. (The amount of regeneration is proportional to the square of
the rotation speed.)
 Lengthen the deceleration time (to decrease the regenerative energy produced per time unit).
 Lengthen the operation cycle, i.e., the cycle time (to decrease the average regeneration power).
Absorbing Regenerative Energy with an External Regeneration
Resistor
If the regenerative energy exceeds the absorption capacity of the Servo Drive, connect an External
Regeneration Resistor. Connect the External Regeneration Resistor to CNA pins 5 and 3 (between
terminals P and B1) of the Servo Drive. Double-check the pin numbers when connecting the resistor
because the Regeneration Resistor may be damaged by burning if connected to the wrong
terminals. The External Regeneration Resistor will heat up to approximately 120
°C. Do not place it
near equipment or wiring that is easily affected by heat. Attach radiator plates suitable for the heat
radiation conditions.
 External Regeneration Resistor
Performance Specifications
Servo Drive
Regenerative energy that can be ab-
sorbed by the internal capacitor
Minimum external regenerative
resistance
J Ω
R7D-BPA5L
R7D-BP01L
620
R7D-BP02L 12 20
R7D-BP01H 8 50
R7D-BP02H
R7D-BP02HH
16 35
R7D-BP04H 16 35
Model
Resis-
tance
Nominal
capacity
Regeneration
absorption at
120°C
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°C ±5%
NC contact
Rated output: 250 VAC, 0.2 A max.