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How to Safely Reform Old Drives

[vc_row][vc_column][vc_column_text]To avoid short circuiting capacitors, it’s important that old drives are reformed. Electrolytic capacitors can experience degradation of their aluminum oxide dielectric insulation if they haven’t been powered up for 12-18 months. Customer Experience Manager Ryan Worzella gives an overview of how the Bonitron Cap Reform can help manufacturers safely solve this problem.

Q: At a high-level, how does the Bonitron Capacitor Reformer work?

A: The capacitor reformer is a portable solution that gradually charges the DC link filter capacitors in a variable frequency drive to restore the degraded dielectric oxide insulating layer found inside the capacitors.

Q: Do I always have to reform old capacitors?

A: When the capacitors sit for prolonged periods of time without voltage present, the dielectric insulating layer will deteriorate, and the capacitors can fail in dramatic fashion if voltage is suddenly applied, such as in the case of line voltage being applied to the drive.  If a drive sits for more than 8 months without power, the dielectric layer in the capacitors can begin to deteriorate. Any drives that have been sitting for more than 12-18 months without voltage applied should really be reformed. It’s safer and in the long-run, more cost-effective.

Q: How can the Bonitron Capacitor Reform help a manufacturer’s bottom line?

A: Reforming, also called re-aging, the capacitors can prevent untimely and costly failures of variable frequency drives.  This pro-active service can eliminate downtime and the need to purchase replacement drives that may have prolonged lead times, especially in higher horsepower applications.

Reforming capacitors ensures that the drives capacitor bank is healthy and ready to go when the drive needs to be placed into service, eliminating downtime and the need to purchase a replacement drive.

Make sure to check out the video to learn more. Ryan provides more detail about capacitor reform and how the Bonitron can help your plant.


Any manufacturer or end user who has VFD’s in their spares stock or has manufacturing lines that have been shuttered/powered down for prolonged periods of time should be concerned. If you have questions or would like to learn more about Sure Controls’ capacitor reform services, make sure to reach out at 800-844-8405 or fill out a contact form online.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column css=”.vc_custom_1667485803474{background-color: #ffffff !important;}”][vc_cta h2=”” shape=”square” color=”black” add_button=”bottom” btn_title=”SHOP PARTS” btn_style=”custom” btn_custom_background=”#d1394b” btn_custom_text=”#ffffff” btn_shape=”round” btn_align=”center” css=”.vc_custom_1667486414363{background-color: #000000 !important;}” btn_link=”url:https%3A%2F%2Fwww.surecontrols-store.com%2F|target:_blank”]

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