Medium voltage variable frequency drives are engineered to deliver reliable performance in tough industrial environments. Yet, even the best systems—like our Siemens Perfect Harmony GH180, WEG MVW01, Benshaw, Toshiba, and Yaskawa drives—can experience failures over time. At IC-Spares, where we not only sell top-quality new drives but also offer flexible rental options, we know that proactive maintenance is the key to avoiding costly downtime. Drawing on decades of field experience, here are five common causes of drive failures and how to tackle them before they disrupt your operations.
1. Aging Capacitors: The Hidden Weak Link
Capacitors form the heart of a drive’s DC bus, supplying the steady power required by the inverter. Many medium voltage drives rely on electrolytic capacitors, which typically have a service life of 7–10 years, similar to the replacement interval for a car’s timing belt. Over time, these components degrade, reducing their ability to hold charge and leading to unexpected shutdowns. Even advanced drives may use film or oil-filled capacitors to extend life, but no capacitor is immune to wear. For example, a Toshiba drive operating well beyond its expected life may start showing erratic behavior due to capacitor aging. Regular inspection and scheduled replacement are essential to maintain reliability.
2. Loose or Corroded Connections: Small Issues, Big Consequences
Vibration and thermal cycles in industrial settings can gradually loosen electrical connections. A loose terminal or corroded connector might seem minor, but it can lead to arcing, oxidation, and even complete circuit failure. In high-power applications—such as those involving a medium voltage drive, a loose connection can create hotspots and damage sensitive components. Routine tightening and cleaning of both internal and external connections can prevent these issues and ensure stable performance.
3. Cooling System Failures: Keeping It Cool Under Pressure
Efficient cooling is critical for medium voltage drives, which generate significant heat during operation. Cooling fans, heat sinks, and filters must work together to help dissipate this heat. In dusty or high-temperature environments, failing fans or clogged filters can cause a gradual rise in internal temperatures. Imagine a scenario where a faulty cooling fan in a Siemens drive leads to overheating, triggering protective shutdowns that halt production. Regular cleaning and preventive checks of the cooling system are vital to keep your drive operating within safe thermal limits.
4. Faulty Low-Voltage Power Supplies: The Unsung Heroes of Control
Every drive relies on low-voltage power supplies to operate its control electronics. These units, often featuring electrolytic capacitors for voltage smoothing, are susceptible to aging and failure. An inconsistent power supply can result in erratic drive behavior or intermittent resets, problems that are notoriously hard to diagnose. For instance, a WEG drive may exhibit random control errors due to a failing power module. Keeping spare power supplies on hand and conducting periodic performance tests can help catch these issues early.
5. Transformer Problems: Early Signs of Catastrophic Failure
Large transformers in medium voltage drives are crucial for stepping down incoming voltage and mitigating harmonic distortion. Despite their robust design, these transformers can suffer from insulation breakdown, overheating, or even vibration-induced arcing. A Benshaw drive with a deteriorating transformer might emit unusual humming sounds or display discoloration on the windings—clear indicators that immediate maintenance is needed. Because transformer failures can lead to extended downtime and expensive repairs, early detection is essential.
Stay Ahead with Proactive Maintenance
Preventative maintenance is the best way to avoid the costly consequences of unexpected drive failures. At IC-Spares, our experienced team is ready to help you develop a customized maintenance plan that keeps your Siemens, WEG, Benshaw, Toshiba, and Yaskawa drives running smoothly. And if you ever need a temporary solution, our rental options ensure you can maintain production without skipping a beat.
Don’t let small issues turn into major failures.
Contact IC-Spares today by phone, email, or visit our website to learn more about our products, rental solutions, and expert maintenance services. Keep your operations running and your downtime minimal—with IC-Spares on your side, you’re always in safe hands.
Source Article: https://emainc.net/5-things-that-cause-failures-in-your-medium-voltage-drives/
