Legacy 1305/1336 to PowerFlex: Cross-Reference Guide

If your plant still runs Allen-Bradley 1305, 1336 PLUS, 1336 IMPACT, or early PowerFlex 4/40/400/700 drives, you are living on borrowed time. Rockwell Automation has discontinued every one of these product lines, and spare parts are getting scarcer and more expensive by the quarter. A proactive migration to the current PowerFlex platform — the 525, 753, and 755 — protects your uptime, your budget, and your access to modern support.

Here you will find a complete cross-reference from legacy drives to their current PowerFlex equivalents, along with the practical details you need to plan a replacement.

Why replace now?

Five reasons to stop sourcing discontinued drives and start planning a migration:

1. End of life means end of support. Rockwell no longer provides firmware updates, technical support, or new spare parts for any of these drives. When one fails, your only option is the secondary market — with unpredictable lead times and no warranty.
2. Spare parts are drying up. Control boards, IGBTs, and power modules for these platforms are increasingly scarce. Prices have doubled or tripled on many components in the past two years.
3. Communication bottleneck. Most legacy drives use DPI or serial protocols. Modern plant networks run EtherNet/IP. Every legacy drive is a protocol island requiring gateways or separate networks.
4. Safety compliance. Current PowerFlex drives include integrated Safe Torque-Off (STO) certified to SIL 2 / PLd. Legacy drives require external safety relays for comparable ratings.
5. Energy efficiency. Modern PowerFlex drives offer improved efficiency through better IGBT technology, sensorless vector control, and PM motor support — reducing energy costs on high-runtime applications.

Legacy to PowerFlex cross-reference table

The table below maps each discontinued drive family to its recommended PowerFlex replacement. In most cases the replacement covers the same or wider power range with better features.

Note on the PowerFlex 400 replacement: For applications at 30 HP or below where encoder feedback is not required, the PowerFlex 525 is also a viable lower-cost replacement for the PowerFlex 400.

Catalog number cross-reference examples

Here are representative cross-reference examples to help you identify the correct replacement:

Important: These are representative examples. The exact replacement depends on your voltage, frame size, enclosure rating, and options. Always verify with the Rockwell Product Compatibility and Migration page or contact Rockwell technical support.

Key considerations before replacing

1. Physical dimensions — will the new drive fit?

This is often the first question and sometimes the hardest to answer. In many cases the current PowerFlex replacement is similar in size or smaller than the legacy drive, but there are exceptions:

• 1305 → PowerFlex 525: The 525 is generally the same width or narrower, and supports side-by-side mounting with zero clearance on the sides. Most 1305 installations can accept a 525 without panel modifications.
• 1336 PLUS → PowerFlex 753: The 753 is typically smaller in depth than the 1336 PLUS at equivalent horsepower ratings. Height and width vary by frame — always check the installation manual dimensional drawings.
• PowerFlex 700 → PowerFlex 755: The 755 is a modular, rack-based architecture. At higher HP ratings it can be larger than the 700. Plan for additional cabinet space or consider a new enclosure.

Action item: Before ordering, measure your existing drive cutout and available cabinet depth. Compare against the replacement drive's installation manual. Check top and bottom clearance for cooling airflow — current drives often require more ventilation clearance.

2. Wiring changes

Power wiring (line and motor connections) is usually straightforward — terminal designations are similar across Allen-Bradley drive generations. However, control wiring will almost certainly change:

• Terminal reassignment: Digital and analog input/output terminal numbers differ between legacy and current drives. You will need to re-land every control wire.
• Signal levels: Some legacy drives use 0–10V analog signals where the new drive may default to 4–20mA, or vice versa. Verify each analog signal's scaling and range.
• Safety wiring: If adding the integrated STO feature, new safety-rated wiring from the safety relay or PLC safety output to the drive STO terminals is required.

3. Parameter mapping

Legacy drives and current PowerFlex drives use completely different parameter numbering systems. There is no one-to-one parameter number mapping. Instead, you will need to:

1. Record all non-default parameters from the legacy drive before removing it.
2. Identify the equivalent function in the new drive's parameter list.
3. Enter the values into the new drive using the HIM keypad, Connected Components Workbench (CCW), or DriveExecutive software.

Rockwell publishes migration guides (e.g., Publication DRIVES-AP007) that list parameter equivalencies for common legacy-to-PowerFlex transitions. Request these from your Rockwell distributor.

4. Communication protocol migration: DPI to EtherNet/IP

If your legacy drives communicate over DPI (DeviceNet Panel Interface) — common on 1336 PLUS, 1336 IMPACT, and PowerFlex 700 installations — migration to EtherNet/IP is the single biggest network change you will face.

Key migration steps for DPI to EtherNet/IP:

• Network infrastructure: Replace DeviceNet cabling (thick/thin trunk cable) with standard Ethernet cabling (Cat5e/Cat6). Add managed Ethernet switches if required.
• PLC program changes: Replace DeviceNet scanner modules and AOIs with EtherNet/IP Module objects. Update all MSG instructions or produced/consumed tags that referenced DeviceNet nodes.
• IP address planning: Assign IP addresses, subnet masks, and (if applicable) VLAN membership for each drive. Use DHCP/BOOTP or manual configuration via the drive HIM.
• Add-On Profiles (AOP): Install the appropriate PowerFlex AOP in Studio 5000 or RSLogix 5000. The AOP provides predefined I/O assembly instances and simplifies configuration.

During a phased migration, you can run DPI and EtherNet/IP networks in parallel until all drives have been converted.

Step-by-step replacement procedure

Follow this general procedure when swapping a legacy drive for its PowerFlex replacement. Adjust based on your site-specific safety and commissioning requirements.

1. Document the existing installation. Record all non-default parameters, wiring terminations (photograph each terminal block), communication settings, and motor nameplate data.
2. Verify the replacement drive selection. Confirm the replacement catalog number matches the application voltage, HP/kW rating, and required features. Cross-reference using the tables above or Rockwell's migration tools.
3. De-energize and lock out. Follow your facility's LOTO (Lock Out / Tag Out) procedure. Verify zero energy at the drive terminals with a voltmeter before proceeding.
4. Remove the legacy drive. Disconnect all power, motor, control, and communication wiring. Remove mounting hardware. Retain the drive for parameter reference if needed.
5. Mount the new PowerFlex drive. Verify dimensional fit and cooling clearance. Secure the drive per the installation manual's torque specifications.
6. Re-wire power and motor connections. Follow the new drive's terminal diagram. Torque all power connections to specification — loose connections are the number one cause of premature drive failure.
7. Re-wire control I/O. Map each legacy control wire to the equivalent new terminal using the wiring documentation from Step 1 and the new drive's terminal assignment table.
8. Configure communication. If migrating from DPI to EtherNet/IP, connect the Ethernet cable, assign the IP address, and add the drive to the PLC project using the appropriate AOP.
9. Enter parameters. Using your documented parameter list and Rockwell's parameter equivalency guide, program the new drive. Run the auto-tune routine if the drive supports it.
10. Test under no-load conditions. Power up and verify direction, speed reference, communication, and fault-free operation.
11. Commission under load. Connect the motor to the driven equipment, ramp up gradually, and verify speed, current draw, and process performance.
12. Update documentation. Record the new catalog number, serial number, firmware version, IP address, and parameter backup file location.

Related resources

• PowerFlex VFD Selection Guide: 525 vs 527 vs 753 vs 755 vs 6000
• PowerFlex 525 vs 753: Detailed Comparison for Machine Builders
• PowerFlex VFD Fault Codes: Complete Troubleshooting Reference

Need replacement PowerFlex drives? Browse our full drives and motion control inventory — we stock PowerFlex 525, PowerFlex 753, and PowerFlex 753 high-HP models with fast shipping.

Frequently asked questions

Can I use my existing motor with a new PowerFlex drive?

In most cases, yes. Enter the motor nameplate data (voltage, current, HP, RPM, service factor) into the new drive's motor parameters and run the auto-tune routine. If the motor is very old or has been rewound multiple times, perform a motor insulation test first — modern drives with faster IGBT switching can stress degraded insulation.

How long does a typical drive replacement take?

For a straightforward one-for-one swap, an experienced technician can complete the physical replacement in 2–4 hours plus 1–2 hours for parameter programming and commissioning. If also migrating from DPI to EtherNet/IP, budget a full shift for the first drive and less for subsequent units as the process becomes routine.

Do I need to update my PLC program when replacing a legacy drive?

It depends on the communication method. If the legacy drive used hardwired analog/digital control and you maintain the same scheme, no PLC changes are needed. If migrating from DeviceNet/DPI to EtherNet/IP, you will need to update the PLC program to replace scanner configurations with EtherNet/IP module configurations. The drive's Add-On Profile (AOP) in Studio 5000 simplifies this considerably.

What if my legacy drive's HP rating falls between two PowerFlex frame sizes?

Always size up to the next available frame size. For example, if you are replacing a 1336 PLUS rated at 40 HP and the PowerFlex 753 is available in 30 HP and 50 HP frames, select the 50 HP frame. Oversizing one frame provides thermal headroom and typically extends the drive's operating life. Never undersize a replacement drive — the short-term cost savings are not worth the risk of nuisance tripping or premature failure under full load conditions.