Simplifying Maintenance: Extending the Life of your PowerFlex 700 Drives

As a general rule of thumb, anything that moves, shakes, or powers up eventually needs maintenance. This is especially true for a factory environment where a PowerFlex 700 series drive will likely be installed.  Keeping a drive in its prime reduces downtime caused by unexpected hardware failures, but you probably already know that. However, what someone might not know is just how to do that. After all, maintaining equipment is a bit of an art form. So, just how does one take care of a PowerFlex 700 drive? Well, that brings us to our first topic.

Routine Inspections

Checking your equipment in intervals is a fairly standard but practical way to ensure everything runs as smoothly as possible. Before we get into it, it is worth reminding you to disconnect all power and ensure that the capacitors inside are fully discharged. Using a multimeter to read voltage (or lack thereof) across the DC Bus terminals (+DC and -DC) is a good way to do so. Then, it would help to get some tools ready, such as a torque screwdriver, soft brush, compressed air, safety gloves, and isopropyl alcohol (IPA).

Getting to the Guts

To begin this routine inspection, unscrew, carefully remove, and set aside the front panel to expose the internal components. From here, you can inspect the boards and modules. You should look for discoloration, burn marks, bulging capacitors, and signs of overheating on the boards or wires. If you notice any of these wear indicators, note which components are directly associated with the damage and consult a technician to determine if it needs to be repaired or replaced. You may also contact us to have your drive repaired by our technicians as well.

Cleaning the Dust and Debris

Now that we have determined that the drive boards are in optimal condition, we can begin cleaning the dust and grime off. Clean the heat sinks, fan vents, and circuit boards using a brush and compressed air. IPA is also good for cleaning grease and oils from the circuit boards. Checking the cooling fans themselves is good practice and is done by clearing the dust off of the blades and spinning them manually to ensure they are smooth and noise free.

Checking Connections

Using the torque screwdriver mentioned before, check each terminal to ensure all connections are secure but not overtightened. While doing so, check the terminal blocks themselves for any signs of corrosion or oxidation. If they happen to be corroded, an electronic cleaner should help. Replacing damaged and frayed connections is also good practice to prevent arcing or faults.

Electrical Health Checks

When it comes to industrial automation, keeping the electrical components in tip-top shape is just as important as the mechanical side of things. A PowerFlex 700 drive depends on stable power and healthy internals to keep your operations humming along without interruptions. So, how do you give these critical components the TLC they deserve? Let’s break it down.

DC Bus Voltage

The DC Bus voltage serves as a snapshot of your drive’s electrical health. Use either the drive’s built-in diagnostic features or an external multimeter to measure this voltage. The manual specifies normal operating ranges for your model—be sure your readings fall within these limits. If the voltage is fluctuating wildly or ripple levels seem high, it’s a red flag. Possible culprits include aging capacitors or issues with the incoming line voltage. Resolving these now prevents bigger headaches later.

Capacitors

Capacitors play a critical role in stabilizing the drive’s power supply, but they don’t last forever. Signs like bulging, leaking, or discoloration on their casing mean it’s time for a replacement. For a deeper dive, test their capacitance with a meter. Compare the readings to the specifications in the manual (or printed on the capacitor itself). If they’re more than 20% off, it’s time to swap them out. The manual also hints at replacing capacitors every 5-7 years in demanding environments to prevent sudden failures.

Dynamic Braking Resistors

When handling heat, the braking resistors are vital for applications requiring dynamic braking. Check for discoloration, cracks, or physical damage; these are telltale signs of overheating or wear. Use a multimeter to measure the resistor’s value and confirm it matches the rated resistance specified in the manual. A resistor that’s out of spec can overheat and lead to drive faults, so replace it promptly if necessary.

Simulate, Monitor, Adjust

After completing your checks, test the drive under controlled conditions. Start with a no-load test and gradually increase to operating conditions. Monitor critical parameters such as DC Bus Voltage, Output Current, and Elapsed Run Time, all of which can be accessed through the drive’s diagnostic features. Watch for any anomalies, such as voltage dips, unusual noises, or error codes. If something feels off, stop the test and troubleshoot immediately.

Proactive Replacement Planning

Even with the best maintenance practices, some components of your PowerFlex 700 drive have a finite lifespan. Rather than waiting for a failure to catch you off guard, a little proactive planning can go a long way in keeping your operations running smoothly. Think of it as staying one step ahead of wear and tear.

Knowing When It’s Time

While regular inspections keep things running smoothly, some wear and tear is unavoidable. Staying ahead of component failures starts with understanding their lifespans:

• Capacitors: The manual suggests a typical service life of 5-7 years, though this can vary depending on the drive’s operating environment. If your drive is exposed to high temperatures or heavy loads, those numbers might skew lower.
• Cooling Fans: Fans are essential for maintaining internal temperatures. If they start making noise, feel sluggish when spun manually, or show excessive dust buildup even after cleaning, it’s time to replace them.
• Dynamic Braking Resistors: These handle significant heat during operation and may show discoloration, cracks, or resistance value shifts over time. Regularly measuring their resistance with a multimeter is a good habit to get into.

Scheduling replacements for these components during planned maintenance windows avoids unexpected breakdowns and keeps your production line on track.

Using Diagnostics to Stay Ahead

The PowerFlex 700 has built-in diagnostics that simplify proactive planning. By monitoring key indicators, you can identify early signs of potential issues before they lead to costly problems. For instance, watch for ripples or fluctuations in DC Bus Voltage, as these can indicate capacitor degradation. Additionally, the drive’s runtime tracking can help you assess when components such as fans and resistors are approaching the end of their expected lifespan. It’s also important to monitor operating temperatures since excessive heat can accelerate wear on components.

Taking advantage of these diagnostic tools helps you plan replacements based on real-time data rather than guesswork. It’s a simple step that makes a big difference in long-term reliability.

Final Thoughts

Even the best maintenance plan can’t anticipate every scenario. Sometimes, components fail ahead of schedule, or you might run into issues that require expertise beyond the scope of your team. That’s where having a reliable partner makes all the difference.

At DOSupply, we offer more than just replacement parts. Our in-house technicians specialize in repairing drives like the PowerFlex 700, as well as PLCs and other automation equipment. Whether it’s troubleshooting a tricky fault, performing a full repair, or sourcing hard-to-find components, we’ve got you covered.

Our dedicated sales team is also here to help you find the exact part you need, whether it’s a new unit or a reconditioned one. With quick turnaround times and expert advice, you can get back to business faster. We also have more articles just like this one, and in fact, we think you would enjoy THIS one next.