Variable frequency drives are valuable assets in any manufacturing environment. When in regular use, their internal components remain stable. When they sit on a shelf or remain powered off for an extended period, the story changes. The capacitors inside the drive begin to deteriorate chemically. This makes them far more vulnerable to failure when the drive is energized again.
Capacitor reforming is a preventative step that helps keep a stored drive from becoming an unexpected expense. It restores the capacitors’ internal stability, allowing the drive to start up safely and operate as intended.
What Happens When Drives Sit Too Long
After roughly eight months without voltage, the insulating layer inside the capacitors starts to weaken. Once this chemical layer degrades, the capacitor can no longer withstand the full voltage. If the drive is powered up under these conditions, the capacitor may fail instantly. This can cause significant damage inside the drive and may require expensive repairs or full replacement.
The risk is even higher for high-horsepower drives with long replacement lead times. A single failure can mean extended downtime, lost productivity, and a costly scramble for replacement parts.
Regular capacitor reforming reduces this risk. Most drives benefit from reforming every eighteen months if they are stored or remain unpowered for long periods.
How Sure Controls Performs Capacitor Reforming
Capacitor reforming must be done carefully. The key is to raise the charge slowly so the capacitor’s internal chemistry has time to rebuild. When this slow, controlled voltage increase is performed correctly, the capacitor regains its ability to handle full load.
Sure Controls technicians use the M3628PCF Portable Capacitor Former by Bonitron to perform this process. This specialized tool allows our team to:
- Apply a controlled, variable DC voltage
- Steadily increase the charge to safe levels
- Hold the capacitor voltage while monitoring its response
- Fully discharge the capacitor after the process
The equipment is portable, so reforming can be performed on site or at our service facility. This flexibility allows us to support stored inventory, backup drives, and drives that have been offline while the machinery was idle or waiting for installation.
Why Professional Reforming Protects Your Investment
Capacitors show no visible signs of instability. A drive can look brand new and still be at risk of failure. Reforming is the only way to confirm it can power up safely.
Partnering with Sure Controls helps you avoid:
- Unplanned downtime
- Damage to high-value drives
- Costly emergency replacements
- Long lead time delays
- Unnecessary waste of spare inventory
Our technicians follow a proven process to prepare your drives for reliable operation and prevent surprises during commissioning.
Protect Your Drives Before Putting Them Back into Service
Stored drives are an essential part of many maintenance programs. To ensure they are ready when you need them, capacitor reforming is essential. Sure Controls provides the expertise, equipment, and support to keep your drives safe and operational.
Call us at 800-844-8405 or use our contact form to schedule capacitor reforming for your equipment.