Comparing PowerFlex 755 and 755TS: Do You Need TotalFORCE?

When spec’ing out a new automation system with a PowerFlex 755 drive, you will notice a few variations. You have the standard 755 with FORCE technology, or the 755TS with TotalFORCE tech. While it initially sounds very similar, the TotalFORCE tech provides a generational leap in performance, all while utilizing the same hardware that we all know and love. But that brings us to the main question: Do you need TotalFORCE?

The Tried and True PowerFlex 755

Let’s take a moment to go over the offerings we have before answering that question. The PowerFlex 755 has been the go-to VFD for countless installations over the past decade, and for a good reason, too. It’s powerful, reliable, and very modular, making it stick out as one of the most flexible options that AB has to offer. Whether you’re automating a conveyor line, fine-tuning a pump motor, or even lifting a crane, chances are that the 755 has done it.

The 755 line covers a wide power spectrum. You’ll find versions for:

• 200–240V (up to 132 kW / 200 HP)
• 380–480V (up to 1,400 kW / 2,000 HP)
• 600V and 690V class systems as well

Modularity is where the 755 shines the most with its long list of plug-in option cards, I/O expansion, encoder feedback, communication adapters (like EtherNet/IP, ControlNet, Profibus, etc.), and safety options such as Safe Torque Off and Safe Speed Monitoring. Not only that, but you also get support for standard and enhanced motor control modes (V/Hz, sensorless vector, and full vector control with encoder feedback), energy-saving features, and an intuitive HIM to top it off.

Powering Through with FORCE Technology

Before TotalFORCE was introduced, FORCE technology was all the craze with ABs drives. It offered a motor control method designed to enhance torque responsiveness and fine-tune motor behavior in real-time. It’s a feedback-based control method that continuously monitors motor torque and adapts the drive’s output to match demand, even as conditions change. That means if your load suddenly increases, the drive doesn’t lag or overshoot, but keeps torque right where it needs to be. This is achieved by:

• Using real-time torque estimation algorithms to maintain consistent output.
• Reacting to load disturbances with tighter control than traditional sensorless vector modes.
• Supporting full closed-loop vector control when paired with an encoder, or open-loop sensorless modes if simplicity is the goal.

One of the most noticeable benefits of using FORCE is during low-speed, high-torque applications. Where some older drives might lose torque or even chatter below a certain RPM, the 755 with FORCE will keep it running smoothly. Even in open-loop sensorless mode, FORCE provides a tighter range of control compared to standard V/Hz or older vector control methods. It also plays well with dynamic braking and ride-through capabilities, making it a flexible option in more demanding environments.

Its only real limitation is that while FORCE gives a solid foundation for motor control, it’s still based on predefined tuning. Once you set those values, the drive sticks to them, which may lead to performance drift if the load changes. But that’s where TotalFORCE comes into play.

The Next Generation PowerFlex 755TS with TotalFORCE

While the T-series 755 doesn’t change in terms of enclosure sizes and ratings, a lot is going on under the hood that makes it a generational leap forward compared to its older brother. Immediately, you will see the new enclosure design, which is a step in the right direction, but the magic lies in the six-pulse 755TS drive with its TotalFORCE capabilities. So what sets it apart from FORCE?

TotalFORCE Technology

TotalFORCE promises to deliver a productivity boost right out of the box by helping to increase throughput, improve uptime, and streamline your operations. Remember when we mentioned that FORCE is a predefined tuning setup per application? TotalFORCE uses adaptive control, which combines the following into one smart package:

• Adaptive Tuning: Continuously fine-tunes control loop gains on the fly, adjusting for changes in mechanical load, temperature, system inertia, and long-term wear. This maintains stable performance even as conditions change.
• Load Observer: Simulates and monitors the motor’s mechanical load in real time. Estimating torque demand, friction, and inertia without relying on external sensors enables tighter torque control, steadier operation during load shifts, and overall smoother performance.
• Bus Observer: Monitors the drive’s DC bus voltage, detecting and compensating for power quality variations to maintain consistent drive behavior.

All of this makes for a drive that adapts to a machine’s changing load. Additionally, TotalFORCE utilizes this information to calculate the life expectancy of drive components based on their usage and environmental conditions. The 755TS will alert the operator if a component is about to fail, whether due to blown fuses, increasing temperatures, or components nearing their end-of-life cycle. This all makes for a drive that is constantly watching, adjusting, and being proactive in the system.

Cranes and hoists also get an uplift in performance due to TorqProve Control. This helps verify load control in lifting applications and compensates for any sway by reducing the swinging of that moving load. More stability and fewer headaches.

What’s the Verdict?

So, back to our original question: Do you need TotalFORCE? While we can’t answer that for you, we can certainly lead you in the right direction.

If your operation mainly consists of consistent loads, operates at steady speeds, or doesn’t need razor-sharp torque control, then the standard 755 is an excellent choice. It gives you solid performance, flexible configuration, and FORCE motor control that’s more than enough for most medium to high-performance applications. It’s a tried-and-true drive that you cannot go wrong with.

On the flipside, if your operation requires frequent speed changes, shifting loads, cranes, and hoists, or the kind of performance where every millisecond counts, then the 755TS starts to make a lot more sense. TotalFORCE provides the adaptive control required for these applications, along with some desirable features such as TorqProve and predictive maintenance. If you want a deeper dive on the 755T series drives, we have an article here for you.

Whatever you decide is best for you, we at DO Supply have you covered. We offer an extensive range of PowerFlex drives, including the 755 and 755TS. Not only that, but we offer repair services to breathe new life into old drives, all backed by our two-year warranty to give that peace of mind. If you are still unsure which drive is best for you, please give us a call, and our experts will be more than happy to assist you. Thank you for reading.