Rockwell has officially classified all 4, 40, and 40P PowerFlex drives as end-of-life as of June 30, 2025. This means these drives will no longer be serviced or sold after the listed date. While all 4M, 40 NEMA, 4X, and 400 drives remain active, we can expect them to experience a life-cycle change in the next 2-3 years.
If your facility relies on these drives for automation, a failing part can cost you more than just time and money–it could shut down your whole line indefinitely while you scramble to find a new drive that suits your needs. That is why it’s important to consider your options for migration sooner rather than later.
Any users of these drives will have three migration options: the PowerFlex 4M, the PowerFlex 523, and the PowerFlex 525. This article will provide an in-depth overview of the three options to equip your panels with the most effective drive possible.
The PowerFlex 4M
One of the members of the 4 series that remains active, the PowerFlex 4M is a potential option for users who require a drive that will fit into their existing framework while remaining eligible for repairs and remanufacturing.
This cost-effective drive uses volts per hertz motor control and is a practical choice for straightforward motor control tasks such as fans, pumps, mixers, and blowers. The 4M supports single-phase power from 120 to 240 volts and three-phase power from 240 to 480 volts, with a maximum power capacity of 15 horsepower or 11 kilowatts. For communication purposes, it supports RS-485 or DSI protocols.
When it comes to pricing, users can expect the 4M to cost:
- $458 to $460 for single-phase drives at 120 volts with 0.25 horsepower, or
- Around $2,080 for three-phase drives at 480 volts with up to 15 horsepower.
As detailed previously, the PowerFlex 4M is a good option for architectures that are specifically made to fit and support PowerFlex 4 Series drives. However, the 4M, while still currently designated as “active” by Rockwell, is nearing the end of its life cycle (much like the 4, 40, and 40P).
If you’re looking for a drive that is more powerful and will be supported for repairs and services for years to come, it is worth considering other options, like the PowerFlex 523 and 525.
The PowerFlex 4M (Courtesy of Rockwell)
The PowerFlex 523
The first of the next generation of PowerFlex drives, the PowerFlex 523 is a clear step forward, offering new features that weren’t available in the previous 4 series.
Stand-out features of the 523 include:
- Flexible programming options: the 523 allows you to customize how the drive operates by adjusting its settings to match your needs, allowing the same drive to be used for different tasks (fans, pumps, conveyors) without needing separate equipment.
- Zero stack: this reduces the amount of space needed for heat dissipation, allowing you to stack the 523 closer to other components and save space.
- Sensorless Vector Control: SVC is a method for controlling a motor’s speed and torque without using physical sensors on the motor. The drive “estimates” the motor’s internal conditions, like speed and rotor position, by analyzing the electrical signals. This helps to improve performance and efficiency and is also more cost-effective.
- Onboard 24V I/O: having physical inputs and outputs on the drive itself means you don’t need a separate controller for basic functions. You can set up simple automation right on the drive itself.
It’s worth keeping in mind that the 523 maxes out at 30HP at 600V, so if your line has a power requirement higher than this, consider another drive. There are also features missing from the 523 that are available on the 525, such as built-in networking and STO; we’ll go over those in the next section.
The PowerFlex 523 starts at $480 for the fractional horsepower single-phase input and can cost up to $5000 for the full stack 480V three-phase 30HP version.
The PowerFlex 523 (Courtesy of Rockwell)
The PowerFlex 525
The next step up from the PowerFlex 523, the 525 offers all of the same key features while adding three notable ones:
- On-board network control: this feature allows you to control your PowerFlex drive through any connection to your facility’s network.
- Safe Torque Off: safe torque off (STO) stops the motor from generating torque, rendering it incapable of generating motion, while still giving the drive power. This ensures personnel safety during maintenance or emergencies without the need to remove power from the entire system. While the 523 does have this feature, it is only usable through hardwired terminals and for general use cases.
- Closed-loop control: uses feedback from sensors to continuously monitor motor performance and adjust the drive’s output. This ensures precise control of speed, position, or torque, even under changing load conditions. It’s ideal for applications requiring high accuracy, stability, and dynamic response, such as robotics, conveyors, and CNC machines.
If these features are important to you, investing in the PowerFlex 525 over the 523 will be worth it for you. If not, consider the 523; it will save you a bit of money and is still an amazing option.
It’s important to consider that the PowerFlex 525 lacks torque and position control capabilities. Also, the PowerFlex 525 has the same power limitations of the 523 (30HP at 480V), so look elsewhere if you require more power.
The PowerFlex 525 starts at $600 for the fractional horsepower single-phase input and can cost up to $6,000 for 30HP with three-phase input.
The PowerFlex 525 (Courtesy of Rockwell)
Which One is Right For Me?
The right equipment with the right capabilities is essential to maximizing your facility’s efficiency, and when an upgrade is on the horizon, it is important to consider all your options.
The PowerFlex 4M, 523, and 525 are all great options when migrating from the 4, 40, or 40P, but one might be the best option for you.
If you’re looking for a simple replacement that will fit your current system architecture and is still supported by Rockwell, the PowerFlex 4M is the best option for you. However, consider that support for this product may not extend for much longer.
If you’re looking for more power with standout features like flexible programming options, zero stack, SVC, and onboard I/O, the PowerFlex 523 will satisfy your needs as the next generation of Rockwell drives.
And if you need all that the 523 offers plus on-board network control, safety STO, and closed-loop control, consider the PowerFlex 525, which delivers on all mentioned fronts.
Finally, remember that both the 523 and 525 top out at 30HP at 600V and lack torque and position control. If these are features you need in your system, consider a different generation of drives. Contact us at HESCO for more options and for help deciding which PowerFlex drive is right for you.