Rockwell Automation · Allen-Bradley

PowerFlex 755 AC Drive

Rockwell's premium AC drive for demanding machine and process applications — EtherNet/IP native, CIP Motion capable, integrated safety to SIL 2/PLd, optional encoder feedback, and full Studio 5000 Logix Designer integration for seamless Logix5000 ecosystem control.

EtherNet/IP NativeCIP MotionSafety SIL 20.75–746 kWStudio 5000
PowerFlex 755 Allen-Bradley · Cat. 20G 1450 RPM 47.2 Hz · 28.5 A RDY FLT EtherNet/IP Dual-port DLR Safety I/O STO/SS1 SIL 2 AC Input L1/L2/L3 AC Output U/V/W Option slots Encoder/PG/Aux AC Motor NEMA/IEC IE3
Power range0.75–746 kW
NetworkDual EtherNet/IP (DLR)
CIP MotionYes — velocity/position
SafetyCIP Safety SIL 2/PLd
Supply200–690 V AC, 3-phase
SoftwareStudio 5000 Logix Designer

Overview

The Allen-Bradley PowerFlex 755 is Rockwell's premium AC drive designed to operate as a native node on the Logix5000 EtherNet/IP network. Unlike drives that use fieldbus adapters, the 755 embeds dual EtherNet/IP ports with DLR (Device Level Ring) directly on the drive's main control board — no adapter module is required for network connectivity. This makes it the drive of choice for Rockwell-centric plants where a CompactLogix or ControlLogix PLC orchestrates multiple drives over EtherNet/IP.

CIP Motion capability allows the PowerFlex 755T (755 with TotalFORCE technology) to function as a coordinated motion axis within a Studio 5000 motion group — velocity control, position control, and torque control via standard PLCopen MC function blocks programmed directly in Studio 5000. No separate servo drive or dedicated motion bus is required for applications demanding moderate positioning accuracy (±0.1% speed, ±2 encoder counts position typical).

The drive's option slot architecture accepts plug-in boards for encoder feedback (PG-B2 incremental, PG-E2 absolute), communication adapters (for non-EtherNet/IP protocols), extended I/O, and energy monitoring. This modular option system means a base drive can be upgraded in the field to add encoder feedback or CIP Safety without replacing the drive — protecting capital investment when applications evolve.

Variable-frequency drive (VFD) unit, the same product class as the Allen-Bradley PowerFlex 755 for AC motor speed control
Compact variable-frequency drive (VFD) unit for AC motor speed control.

Key Features

  • Native dual EtherNet/IP with DLR
    Two embedded EtherNet/IP ports with DLR topology support eliminate external switches for ring redundancy. In a machine with 10 drives, ring topology wiring reduces EtherNet/IP cable runs by 50% and provides automatic ring recovery in under 3 ms if a cable fails.
  • TotalFORCE with CIP Motion (755T)
    The PowerFlex 755T variant adds TotalFORCE technology — a proprietary torque-vector control algorithm with 2 ms torque response and ±0.5% speed accuracy open-loop. CIP Motion enables the 755T to participate as an EtherNet/IP motion axis in Studio 5000, synchronised with Kinetix servo axes on the same motion group for multi-drive coordination.
  • CIP Safety — SIL 2/PLd integrated
    The optional safety option board adds CIP Safety over EtherNet/IP — STO, SS1, SS2, SLS, SDI, and SSM functions certified to SIL 2 / PLd. Safety I/O uses the same EtherNet/IP cable as the standard drive I/O, eliminating dedicated safety bus wiring and the associated hardwired safety relay panels.
  • Energy monitoring — kWh, power factor, THD
    The 755's embedded energy monitor tracks kWh consumption, power factor, real/reactive/apparent power, and total harmonic distortion without external power meters. Data is accessible via EtherNet/IP or the drive's web server, enabling ISO 50001 energy management compliance reporting directly from drive data.

Technical Specifications

PowerFlex 755 — Key Specifications
Power range0.75–746 kW (208–240 V / 400–480 V / 600–690 V)
Input voltage200–240 V AC / 380–480 V AC / 500–690 V AC, 3-phase
Output frequency0–400 Hz
Control modesV/Hz, sensorless vector, closed-loop vector, CIP Motion (755T)
EtherNet/IPDual 10/100 Mbps with DLR topology support (embedded)
SafetyCIP Safety SIL 2 / PLd (STO, SS1, SS2, SLS, SDI, SSM — option board)
Option slots6 × option slots (encoder feedback, I/O, communication, safety)
Protection classIP20 standard; IP54 (NEMA 12) enclosure option
Ambient temperature0 °C to +50 °C (standard); derating above 40 °C for high frames
Overload capacity110% for 60 s (general purpose); 150% for 3 s (high overload)
SoftwareStudio 5000 Logix Designer V32+; Connected Components Workbench

Typical Applications

  • Centrifugal pumps and fans: V/Hz or sensorless vector with integrated PID and sleep/wake energy management
  • Conveyors and packaging: DLR ring topology across 12+ drives; CIP Safety E-stop on EtherNet/IP
  • Mixers and agitators: Torque proving with load cell feedback; run-up torque boost for viscous media
  • Winders and unwinders: 755T CIP Motion for tension control in paper, film, and textile winding
  • Crane and hoist: Sensorless vector with anti-sway positioning and flux braking

Sources & Further Reading

  • Rockwell Automation — PowerFlex 755 User Manual (Publication 750-UM001)
  • Rockwell Automation — CIP Motion Reference Manual (1756-RM084)
  • ODVA — CIP Safety Specification, Volume 5
  • IEC 61800-5-2:2016 — Safety requirements for adjustable speed drives