Yaskawa CACR-SR Servo Drive Modules CACR-SR 44S

Technical Dossier

Product Details And Specifications

Yaskawa CACR-SR Series Technical Notes

The Yaskawa CACR-SR series represents one of the most widely deployed analog servo drive families in global heavy industry. Installed across petrochemical complexes, nuclear power auxiliary systems, offshore drilling platforms, and continuous-process refineries, the CACR-SR line served as the motion control backbone for Yaskawa's Motoman robot controllers and standalone CNC servo axes throughout the 1980s and 1990s. Its robust analog command interface, combined with Yaskawa's proprietary SERVOPACK architecture, made it the default choice for OEMs requiring deterministic torque response in high-duty-cycle environments. Installed base estimates place active CACR-SR units in the tens of thousands globally, the majority operating in facilities where full system replacement is economically or operationally impractical.

The Evolution of CACR-SR Architecture

The CACR-SR series was introduced as a successor to Yaskawa's earlier CACR-IR and CACR-PR families, transitioning from relay-logic current control to fully transistorized PWM drive stages. Early CACR-SR units (circa 1983–1988) used discrete analog signal conditioning boards with ±10 V velocity command inputs and resolver-based feedback. Mid-generation revisions (1989–1994) introduced improved IGBT switching stages, reducing heat dissipation and enabling higher continuous current ratings in the same mechanical envelope. Late-series variants added optional serial diagnostic ports compatible with Yaskawa's MEMOBUS protocol, bridging the gap toward the fully digital SGDA and SGDH SERVOPACK families that succeeded them.

Compatibility across CACR-SR sub-variants is constrained by motor feedback type (resolver vs. encoder), power supply voltage (200 V AC vs. 400 V AC three-phase), and continuous output current rating. Mixing sub-series without verifying these parameters against the motor nameplate and controller command card is a documented source of field failures. DriveKNMS maintains cross-reference tables for all known CACR-SR variants to support accurate replacement sourcing.

CACR-SR Full Catalog & Functionalities (SKU List)

The following SKUs represent verified members of the Yaskawa CACR-SR servo drive family, classified by output current rating and application class:

CACR-SR 02AC1: 200 V, 2 A continuous, resolver feedback, single-axis analog velocity drive.
CACR-SR 03AC1: 200 V, 3 A continuous, resolver feedback, compact panel-mount servo amplifier.
CACR-SR 05AC1: 200 V, 5 A continuous, resolver feedback, standard industrial servo axis.
CACR-SR 10AC1: 200 V, 10 A continuous, resolver feedback, mid-range torque servo drive.
CACR-SR 20AC1: 200 V, 20 A continuous, resolver feedback, high-torque axis amplifier.
CACR-SR 44S: 200 V, 44 A continuous, resolver feedback, heavy-duty servo drive for large-frame Motoman axes.
CACR-SR 02BC1: 400 V, 2 A continuous, resolver feedback, three-phase high-voltage variant.
CACR-SR 05BC1: 400 V, 5 A continuous, resolver feedback, 400 V class standard axis drive.
CACR-SR 10BC1: 400 V, 10 A continuous, resolver feedback, 400 V mid-range servo amplifier.
CACR-SR 20BC1: 400 V, 20 A continuous, resolver feedback, 400 V high-current drive.
CACR-SR 44BC1: 400 V, 44 A continuous, resolver feedback, 400 V heavy-duty servo amplifier.
CACR-SR 02AC3: 200 V, 2 A, encoder feedback variant, compatible with incremental encoder motors.
CACR-SR 05AC3: 200 V, 5 A, encoder feedback variant, standard encoder-based axis.
CACR-SR 10AC3: 200 V, 10 A, encoder feedback variant, mid-range encoder servo drive.
CACR-SR 20AC3: 200 V, 20 A, encoder feedback variant, high-current encoder-compatible amplifier.
CACR-SR 44AC3: 200 V, 44 A, encoder feedback variant, large-axis encoder servo drive.
CACR-SR 02BC3: 400 V, 2 A, encoder feedback, 400 V class compact encoder drive.

Sourcing Hard-to-Find & Obsolete CACR-SR Parts

The CACR-SR series reached end-of-production status with Yaskawa's transition to the SGDA and subsequently SGDH and SGDV SERVOPACK platforms. Official Yaskawa factory support, including spare parts supply and repair services, has been discontinued for the majority of CACR-SR variants. This creates a documented supply gap for facilities operating legacy Motoman robot systems (UP series, HP series, SK series) and standalone CNC machines that were designed around CACR-SR drive specifications.

Quality Control for the CACR-SR Range

CACR-SR drives present specific test challenges due to their analog signal architecture and resolver-based feedback circuits. Standard digital servo drive test benches are not directly applicable. DriveKNMS employs a dedicated analog servo test station configured to replicate the ±10 V velocity command interface and resolver excitation signals used by CACR-SR drives in service.