Why the Allen-Bradley 1336 PLUS II Still Delivers for Legacy Systems

Are you still running an Allen-Bradley 1336 PLUS II drive? You’re not alone. While many facilities have upgraded to modern drives like the PowerFlex 750 series, the 1336 PLUS II remains a go-to solution for emergency replacements and systems not yet ready for complete modernization.

In this guide, we’ll cover its key specs, control features, communication options, and when it still makes sense to use one—plus tips to help you plan your next upgrade.

Allen-Bradley 1336 PLUS II Overview

The 1336 PLUS II adjustable frequency AC drive is a compact, high-performance solution from Rockwell Automation designed for precise motor speed control in a wide range of industrial environments.

Commonly found in systems like conveyors, pumps, machine spindles, and fans, this legacy drive supported robust performance with flexible installation options—making it a staple in facilities throughout the early 2000s.

While obsolete today, it remains a valuable like-for-like replacement for systems with specific power and interface requirements.

Key Technical Specifications

The 1336 PLUS II was available in multiple voltage and horsepower ranges to support varied industrial applications:

• 200–240V AC Input: 0.5 to 125 HP

• 380–480V AC Input: 0.5 to 600 HP

• 500–600V AC Input: 1 to 600 HP

This range gave engineers plenty of flexibility when matching the drive to motor requirements—especially in high-horsepower environments like material handling or water treatment.

⚙️ Need a replacement drive?

Browse available 1336 PLUS II units here or contact us for a quote.

Control Modes: SVC and V/Hz Operation

One of the standout strengths of the 1336 PLUS II is its flexible motor control. It supports two primary control modes, making it adaptable to both basic and performance-driven applications:

1. Volts-per-Hertz (V/Hz) Control

• Ideal for standard applications that don’t require tight torque control

• Maintains a constant voltage-to-frequency ratio

• Supports multiple motors on a single drive

• Simple to configure and cost-effective

2. Sensorless Vector Control (SVC)

• Provides high starting torque and precise speed regulation

• No feedback devices required—reduces wiring complexity

• Best for low-speed, high-torque demands

Enhanced SVC Features Include:

• Fast Flux-Up: Accelerates large motors more quickly

• Up to 250% Acceleration Torque: For heavy-load start-ups

• Low-Speed Operation (as low as 15 RPM): Without compromising torque

• Adaptive Current Limit (ACL) Tuning: Helps optimize drive response in real-time
  

🎯 Whether you're driving a heavy-duty conveyor or a variable load pump, the 1336 PLUS II still delivers strong performance in legacy setups.

Legacy Communication & Integration

While the 1336 PLUS II’s communication protocols are considered outdated today, they were built with flexibility in mind—offering seamless integration with many older PLC systems still running in plants worldwide.

Supported Interfaces Include:

• RS-232 / RS-422 / RS-485 serial communication

• Remote I/O with classic PLCs like PLC-5 and SLC 500

• SCANport-Compatible Modules:

  • Connect to DeviceNet, Flex I/O, and other Rockwell systems

  • Enable limited networking without full EtherNet/IP support

These options made the 1336 PLUS II ideal for facilities standardizing on Rockwell Automation platforms during its production years.

🔌 Still using SCANport or Remote I/O?
The 1336 PLUS II may be your fastest route to restoring production without re-engineering your control system.

💡 Planning to modernize?
Check out our PowerFlex 750 Modernization Guide to start mapping your upgrade path.

Built-In Features That Still Deliver

Despite being a legacy product, the 1336 PLUS II was well ahead of its time in terms of onboard functionality. It offered a range of smart features that allowed operators to reduce reliance on external PLC programming for certain tasks.

Key Features Include:

• Auto-Tuning:
  Automatically identifies motor parameters to optimize drive response and performance.

• Process PI Controller:
  Enables basic process control functions (e.g., maintaining pressure or flow) without an external controller.

• Auto Economizer Mode:
  Adjusts output voltage during light load conditions to improve energy efficiency.

• Step Logic & Traverse Functions:
  It supports simple motion sequences and repetitive logic tasks without a PLC, making it ideal for applications like machine feeding or pattern cutting.

Reliable Protection & Safety Features

The 1336 PLUS II was engineered for industrial environments where uptime matters. It includes:

• Overcurrent, overvoltage, and stall protection

• Built-in I²t electronic motor overload protection

• Fault reset input for fast recovery

• Real-time alarms and diagnostics via HIM or SCANport interface
  

🛡️ Just because it’s old doesn’t mean it’s unprotected. These drives still offer a dependable safety foundation while planning your system upgrade.

When a 1336 PLUS II Still Makes Sense

While we don’t recommend installing 1336 PLUS II drives in new builds, there are critical scenarios where they remain the smart choice:

✅ Emergency Replacements:
Your system goes down and needs a fast, like-for-like swap without changing wiring, logic, or cabinet layout.

✅ Legacy PLC Integration:
Your existing system uses SCANport or Remote I/O, and full modernization isn’t feasible—yet.

✅ Budget Constraints or Timing Issues:
You’re in the planning stages of a plant upgrade, but can’t afford downtime now.

✅ Temporary Bridging Solution:
Keep production running with a known, proven drive while you prepare your future automation roadmap.

⚙️ Need help finding a compatible replacement or want to discuss short-term vs. long-term strategies?

Our team can help you source the right 1336 PLUS II drive or start planning your transition to a PowerFlex 750 series solution.

Get Expert Help Today

At Industrial Automation Co., we specialize in helping facilities like yours extend the life of legacy systems while preparing for modern upgrades. Whether you're looking for a refurbished 1336 PLUS II, a PowerFlex retrofit, or just honest guidance, we’ve got your back.

🛒 Browse 1336 PLUS II Drives
📘 Read the PowerFlex 750 Modernization Guide
📞 Contact Our Drive Specialists