Variable frequency drives put your largest, hardest-working motors at risk of bearing failure. Shaft grounding protects them.
Mining and metals run on big motors in punishing conditions, and almost all of them run on variable frequency drives (VFDs). On motors this large, the shaft currents those drives create don’t just shorten bearing life, they turn a preventable problem into a long, costly outage.
SGS shaft grounding stops those currents from ever reaching the bearings.
Trusted by Leading Mining & Metal Companies
Just a few mining companies that have installed SGS shaft grounding are Specialty Minerals, Inc., Ash Grove Cement Company, and Asbury Advanced Materials, helping protect critical motors from bearing damage and premature failure.
An electrical bearing failure on a small fan is a nuisance. On a mill drive, a crusher, or a rolling-line motor, it’s a major outage.
These motors are large, expensive, and often built to order, so a damaged bearing can mean weeks of lead time and lost production while you wait on a replacement.
The conditions make it worse. Dust, grit, heat, moisture, and corrosive process chemicals are hard on every motor, and they give electrical bearing damage a faster path to failure than it would ever find in a clean plant.
Where Shaft Voltage Threatens Mining and Metals Motors
Any VFD-driven motor can develop shaft voltage. Across mining and metals operations, that includes some of the largest, most critical motors on site.
Mining and mineral processing:
- Crushers, SAG and ball mill drives
- Slurry, dewatering, and process pumps
- Conveyors, stackers, and reclaimers
- Fans, blowers, and thickener drives
Steel and metals production:
- Rolling mill and finishing-line drives
- Furnace, fan, and blower motors
- Pickling-line and process pumps
- Casters, coilers, and material-handling conveyors
Large Motors Face a Second Threat: Circulating Currents
Smaller motors are damaged mainly by high-frequency voltage discharging across a single bearing. Large motors have an added problem. Their size lets circulating currents flow down the shaft and through the bearings at both ends, a form of damage that grounding at one end alone can’t fully stop.
That’s why big mill, crusher, and rolling-line drives often need grounding at both ends of the shaft. The SGS SR Series is built for exactly that, protecting large-frame motors where circulating currents are in play.
SGS Shaft Grounding, Sized to Your Motors
SGS Shaft Grounding Systems divert shaft current safely to the motor frame, away from the bearings, whatever the motor size:
- CR Series: our axially mounted, sealed-brush system for standard NEMA and IEC frame motors. The right fit for the many pumps, fans, and conveyor motors across a site.
- SR Series: a split-ring system for large-frame motors, grounding both shaft ends where circulating currents are a concern, such as mill, crusher, and rolling-line drives.
- DR Series: a solid-ring system for motors that can be uncoupled, ideal for planned retrofits during a scheduled outage.
Why SGS Stands Up to Mining and Metals
Built for abrasive, corrosive, punishing conditions.
Whichever system your motors call for, SGS shaft grounding is engineered for demanding industrial conditions, where dust, grit, heat, moisture, and corrosive chemicals defeat lesser protection.
- Matched to every motor: the CR, SR, and DR Series cover everything from standard pumps and fans to the largest mill and rolling-line drives, so a single supplier protects your whole site.
- Fast availability: same-day shipping within the US and rapid international delivery, so even a remote site isn’t held up waiting on a protective part.
- Built for continuous duty: long service intervals and simple rebuild kits for motors that run around the clock.
- Proven and US-made: 40 years of shaft grounding experience, manufactured in the USA.
Whether you’re protecting new drive motors or retrofitting the fleet you already run, SGS systems install in the field without disrupting production.
FAQs
Do large mill and crusher motors need different protection than smaller ones?
Often, yes. Large-frame motors can develop circulating currents that require grounding at both shaft ends, which the SR Series provides. Smaller motors across the site are covered by the CR Series.
How quickly can you get parts to a remote site?
As fast as your operation needs. SGS ships same-day within the US and delivers rapidly worldwide, so even a remote mine or mill isn’t left waiting weeks on a small protective part while a critical motor sits at risk.
Can shaft grounding handle the vibration and shock loads of crushers and mills?
Yes. SGS shaft grounding is engineered for heavy industrial duty, holding a reliable path to ground on motors that run under the constant vibration and shock loads of crushers, mills, and conveyors.
Protect the Motors You Can't Afford to Lose
Tell us about your mill, crusher, pump, and drive motors, and we'll recommend the right shaft grounding solution for your site.