Allen‑Bradley 20G1AND125AA0NNNNN PowerFlex755 Variable Frequency Drive Unit

Module Feature

20G1AND125AA0NNNNN is Allen‑Bradley PowerFlex755 series air-cooled variable frequency drive, frame 6 open type construction. It supports V/Hz control, sensorless vector and closed-loop vector control modes.

It is equipped with built-in dynamic braking transistor and EMC filter, AC input with pre-charge circuit, no DC terminals reserved. It can be matched with HIM human interface module and EtherNet/IP communication option card. It has multiple protection functions including overcurrent, overvoltage, over-temperature and overload, suitable for continuous operation of industrial fans, water pumps and conveying equipment.

Working principle

Three-phase AC mains power is rectified into DC bus voltage, and then the IGBT power module outputs adjustable frequency and adjustable voltage AC power to drive motor.

The drive collects motor encoder feedback signal to realize high-precision closed-loop speed and torque control. Internal real-time monitoring circuit judges operating status and triggers protection interlock once fault occurs. Running data and alarm information can be uploaded to Logix PLC through industrial network.

Onboard components

Rectifier module, IGBT power amplifier unit, switching power supply board, main control CPU board, current and voltage sampling circuit, cooling fan assembly, dynamic braking transistor, terminal block and expansion slot.

LED indicators

Front panel LEDs indicate power ready, drive running, fault alarm, network communication and interlock protection status.

Hardware self‑diagnosis

Self-check covers bus voltage anomaly, output overcurrent, amplifier overheat, fan failure, communication module loss and encoder feedback error. Fault codes can be viewed via HIM panel or Studio5000 software.

Programming softwareStudio5000 Logix Designer for drive parameter tuning, fault log reading, network configuration and firmware upgrade.

Electrical & Process Parameters

Model:20G1AND125AA0NNNNN Brand:Allen‑Bradley Series:PowerFlex755 Voltage:480V 3-phase Output current:125A Rating:100HP ND /75HP HD Cooling:Air cooled Enclosure:Open type IP20 Function:AC motor closed-loop speed and torque control

Mechanical & Structure

Mounting:Vertical cabinet mounting Protection class:IP20 Housing:Metal open frame chassis

Environmental

Operating temperature:-20℃ ~ +45℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing Certification:UL, CE compliant Status:Discontinued AB original VFD spare

Installation

Install inverter in well-ventilated cabinet and keep enough clearance for heat dissipation. Connect three-phase mains power and motor output cable separately.

Set motor nameplate parameters, acceleration/deceleration time and protection threshold. Complete auto-tune and limit interlock test before formal operation. Clean radiator dust periodically.

Interface

Mains power terminals, motor output terminals, 24V auxiliary power terminals, encoder feedback port, option card expansion slot, relay alarm contacts.

Diagnostic

Drive fault trip: Overload, motor short circuit or bus overvoltage.

Motor follow error: Encoder wiring loose, parameter improper or mechanical jam.

Communication offline: Option card abnormal, network cable fault or IP address conflict.

Product Brief

Allen‑Bradley 20G1AND125AA0NNNNN PowerFlex755 air-cooled inverter, 480V 125A, 100HP normal duty, built-in DB transistor and EMC filter, used for industrial pump, fan and conveyor motor speed control.